Ablation: Destruction of part or all of an organ or structure.
Abscess: A purulent (i.e., containing, discharging, or causing the production of pus) collection of fluid separated from surrounding tissue by a wall composed of inflammatory cells and adjacent organs. It usually contains necrotic debris, bacteria, and inflammatory cells.
Acanthosis nigricans: A skin condition characterized by dark, thickened, velvety patches, especially in the folds of skin in the armpits, groin, and back of the neck that is often associated with insulin resistance.
Acaricide: A chemical that kills mites and ticks.
Acetaldehyde: A by-product of alcohol metabolism.
Acetylcholinesterase: An enzyme that breaks down unused acetylcholine in the synaptic cleft. This enzyme is necessary to restore the synaptic cleft so it is ready to transmit the next nerve impulse
Achlorhydria: Low level or absence of gastric acid in the stomach.
Acidemia: An increase in the hydrogen ion concentration in the blood or a fall below normal in pH.
Acidosis: Any pathologic state that leads to acidemia.
Acromegaly: A pathologic condition characterized by excessive production of growth hormone during adulthood after epiphyseal (growth plate) fusions have completed.
Action potential: A rapid change in the polarity of the voltage of a cell membrane from negative to positive and back to negative. A wave of electrical discharge that travels across a cell membrane.
Acute chest syndrome: An acute respiratory complication of sickle cell disease characterized by chest pain, fever, and pulmonary infiltrates.
Acute coronary syndromes: Ischemic chest discomfort at rest most often accompanied by ST-segment elevation, ST-segment depression, or T-wave inversion on the 12-lead electrocardiogram; further, it is caused by plaque rupture and partial or complete occlusion of the coronary artery by thrombus. Acute coronary syndromes include myocardial infarction and unstable angina. Former terms used to describe types of acute coronary syndromes include Q-wave myocardial infarction, non-Q-wave myocardial infarction, and unstable angina.
Acute disorder: An acid–base disturbance that has been present for minutes to hours.
Acute kidney injury: Spectrum of acute changes in kidney function ranging from minor changes to those requiring renal replacement therapy.
Acute otitis media: Inflammation of the middle ear accompanied by fluid in the middle ear space and signs or symptoms of an acute ear infection.
Acute tubular necrosis: Form of acute kidney injury that results from toxic or ischemic injury to the cells in the proximal tubule of the kidney.
Addiction: A primary, chronic, neurobiologic disease, with genetic, psychosocial, and environmental factors influencing its development and manifestations. It is characterized by behaviors that include one or more of the following: impaired control over drug use, compulsive use, continued use despite harm, and craving.
Adenocarcinomas: Malignant tumor originating in glandular tissue.
Adenoma: A nonmalignant tumor of the epithelial tissue that is characterized by glandular structures.
Adenomatous polyposis coli (APC) gene: A tumor suppressor gene (see definition) that is one of the first genes mutated in the development of colon cancer. Patients with familial adenomatous polyposis (FAP) are born with this gene mutated.
Adjuvant chemotherapy: Treatment given after the primary surgical treatment and is designed to eliminate any remaining cancer cells that are undetectable with the goal of improving survival.
Adjuvant therapy: Therapy that supplements or follows primary therapy to prevent the risk of recurrence.
Adnexal: Adjacent or appending as the fallopian tubes and ovaries are to the uterus.
Adrenalectomy: Surgical removal of an adrenal gland.
Adrenocorticotropic hormone: A hormone secreted by the anterior pituitary that controls secretion of cortisol from the adrenal glands. Also referred to as corticotropin.
Adverse drug reaction (ADR): As defined by the American Society of Health-System Pharmacists, ADR is any unexpected, unintended, undesired, or excessive response to a medication that: requires discontinuing the medication; requires changing the medication; requires modifying the dose (except for minor dosage adjustments); necessitates admission to the hospital; prolongs stay in a health care facility; necessitates supportive treatment; significantly complicates diagnosis; negatively affects prognosis; or results in temporary or permanent harm, disability, or death.
Aeroallergen: An airborne substance that causes an allergic response.
Afterload: The force against which a ventricle contracts that is contributed to by vascular resistance, especially of the arteries, and by physical characteristics (mass and viscosity) of the blood.
Ageism: Discrimination against aged persons.
Air embolus: An obstruction in a small blood vessel caused by air that is introduced into a blood vessel and is carried through the circulation until it lodges in a smaller vessel.
Akathisia: Motor or subjective feelings of restlessness.
Akinesia: Lack of movement.
Alcohol dehydrogenase: An enzyme that degrades ethanol in the gut and liver.
Aldosterone: A hormone produced in and secreted by the zona glomerulosa of the adrenal cortex. Aldosterone acts on the kidneys to reabsorb sodium and excrete potassium. It is also a part of the renin-angiotensin-aldosterone system that regulates blood pressure and blood volume.
Alkalemia: A decrease in the hydrogen ion concentration of the blood or a rise above normal in pH.
Alkalosis: Any pathologic state that leads to alkalemia.
Allodynia: Pain that results from a stimulus that does not normally cause pain.
Allogeneic: In the setting of stem cell transplantation, the scenario in which the donor is a genetically similar but not identical to the recipient. The donor is frequently a sibling or a matched related donor. A matched unrelated donor may be used in the absence of a related donor.
Allograft: Tissue or organ transplanted from a donor of the same species but different genetic makeup; recipient’s immune system must be suppressed to prevent rejection of the graft.
Allograft survival: After the transplant procedure, when the transplanted organ continues to have some degree of function, from excellent to poor.
Allorecognition: Recognition of the foreign antigens present on the transplant organ or the donor’s antigen presenting cells.
Alopecia: Hair loss.
Amenorrhea: The absence or discontinuation of regular menstrual periods.
γ-Aminobutyric acid: An inhibitory amino acid found in the central nervous system.
Amotivation: Apathy, loss of effectiveness, and diminished capacity or willingness to carry out complex, long-term plans, endure frustration, concentrate for long periods, follow routines, or successfully master new material.
Amygdala: Part of the limbic system that mediates emotions and helps to coordinate the response to threatening or stressful situations.
Amylase: An enzyme that catalyzes the hydrolysis of starch into simpler compounds.
Amylin: A 37-amino acid polypeptide hormone that is secreted from the β-cells of the pancreas in response to nutrients. Mechanisms of action include slowing gastric emptying, suppressing postmeal glucagon secretion, and suppressing appetite.
Amyloid: Any of a group of chemically diverse proteins which are composed of linear nonbranching aggregated fibrils.
Anaphylactic/anaphylaxis: Immediate, severe, potentially fatal hypersensitivity reaction induced by an antigen.
Anaphylactoid: An anaphylactic-like reaction, similar in signs and symptoms but not mediated by IgE. The drug causing this reaction produces direct release of inflammatory mediators by a pharmacologic effect.
Anastomosis: The connection of two hollow organs to restore continuity after resection or to bypass disease process that is not resectable.
Anemia: A reduction below normal in the concentration of hemoglobin in the body that results in a reduction of the oxygen-carrying capacity of the blood.
Anemia of chronic kidney disease: A decline in red blood cell production caused by a decrease in erythropoietin production by the progenitor cells of the kidney. As kidney function declines in chronic kidney disease, erythropoietin production also declines, resulting in decreased red blood cell production. Other contributing factors include iron deficiency and decreased red blood cell lifespan, caused by uremia.
Anergy: A reduction or lack of an immune response to a specific antigen.
Aneuploidy: Abnormal number of chromosomes.
Angina: Discomfort in the chest or adjacent areas caused by decreased blood and oxygen supply to the myocardium (myocardial ischemia).
Angina pectoris: Severe constricting pain in the chest, often radiating from the precordium to a shoulder (usually left) and down the arm, due to ischemia of the heart muscle usually caused by a coronary disease.
Angioedema: Swelling similar to urticaria (hives), but the swelling occurs beneath the skin instead of on the surface. Angioedema is characterized by deep swelling around the eyes and lips and sometimes of the hands and feet. If it proceeds rapidly, it can lead to airway obstruction and suffocation, and it should therefore be treated as a medical emergency.
Angiogenesis: The formation of new blood vessels.
Anhedonia: Inability to experience pleasure.
Anorexia: An eating disorder generally characterized by distorted body image, fear of weight gain, unwillingness to eat, and restrictive diet; may also refer to loss of appetite and serious weight loss as a result of disease.
Anoxia: A lack of oxygen.
Anterograde amnesia: Memory loss affecting the transfer of new information or events to long-term storage.
Antiangiogenic: Preventing or inhibiting the formation and differentiation of blood vessels.
Anticoagulant: Any substance that inhibits, suppresses, or delays the formation of blood clots. These substances occur naturally and regulate the clotting cascade. Several anticoagulants have been identified in a variety of animal tissues and have been commercially developed for medicinal use.
Antimicrobial prophylaxis: Use of an antimicrobial to prevent an infection.
Antiproteinase: A substance that inhibits the enzymatic activity of a proteinase.
Antrectomy: A surgical excision of the wall of the antrum, the region of the stomach that produces the hormone gastrin.
Anuria: Urine output of less than 50 mL over 24 hours.
Anxiogenic: Something that promotes or causes anxiety.
Aphakia: The absence of a lens in the eye.
Aphasia: Impairment of language affecting the ability to speak and to understand speech.
Aphthous ulcer: A small superficial area of ulceration within the gastrointestinal mucosa, typically found in the oral cavity.
Apoptosis: Programmed cell death as signaled by the nuclei in normally functioning cells when age or state of cell health and condition dictates.
Arcuate scotoma: An arc-shaped area of blindness in the field of vision.
Arthralgia: Pain in joints.
Arthrocentesis: Puncture and aspiration of a joint. Certain drugs can be injected into the joint space for a local effect.
Arthus reaction: Local inflammatory response due to deposition of immune complexes in tissues.
Articular: Related to a joint or joints.
Ascites: Accumulation of fluid within the peritoneal cavity.
Asterixis: A flapping tremor of the arms and hands that is seen in patients with end-stage liver disease.
Astringent: A substance that causes tissues to constrict, resulting in a drying effect of the skin.
Ataxia: Defective muscular coordination, possibly manifested by a staggering gait.
Atelectasis: Decreased or absent air in a partial or entire lung, with resulting loss of lung volume.
Atherosclerosis: Accumulation of lipids, inflammatory cells, and cellular debris in the subendothelial space of the arterial wall.
Atopy: A genetic predisposition to develop type I hypersensitivity reactions against common environmental antigens. Commonly seen in patients with allergic rhinitis, asthma, and atopic dermatitis.
Atresia: Congenital absence of a normal opening or normally patent lumen.
Autograft: A tissue or organ grafted into a new position in or on the body of the same individual.
Autologous: In the setting of stem cell transplantation, the scenario in which the donor and recipient are the same person.
Automaticity: Ability of a cardiac fiber or tissue to spontaneously initiate depolarizations.
Autonomic (nervous system): The parasympathetic and sympathetic nerves that control involuntary actions in the body.
Azoospermic: Having no living spermatozoa in the semen, or failure of spermatogenesis.
Bacteriuria: Presence of bacteria in urine.
Barium enema: A diagnostic test using an x-ray examination to view the lower gastrointestinal tract (colon and rectum) after rectal administration of barium sulfate, a chalky liquid contrast medium.
Basal ganglia: Cluster of nerve cells deep in the brain that coordinate normal movement.
Bence-Jones proteins: Light-chained immunoglobulins found in the urine.
Bilateral: Pertaining to both sides.
Bilateral salpingo-oophorectomy: Surgical excision (removal) of both ovaries.
Bile acids: The organic acids in bile. Bile is the yellowish-brown or green fluid secreted by the liver and discharged into the duodenum where it aids in the emulsification of fats, increases peristalsis, and retards putrefaction; contains sodium glycocholate and sodium taurocholate, cholesterol, biliverdin and bilirubin, mucus, fat, lecithin, and cells and cellular debris.
Biliary sludge: A deposit of tiny stones or crystals made up of cholesterol, calcium bilirubinate, and other calcium salts. The cholesterol and calcium bilirubinate crystals in biliary sludge can lead to gallstone formation.
Bioavailability: The amount of agent that is absorbed orally relative to an equivalent dose administered intravenously.
Biopsy: A procedure that involves obtaining a tissue specimen for microscopic analysis to establish a precise diagnosis.
Blastopore: A fungal spore produced by budding.
Blood dyscrasias: Any abnormality in the blood or bone marrow’s cellular components such as low white or red blood cell count or low platelets
Blood urea nitrogen (BUN): A waste product in the blood produced from the breakdown of dietary proteins. The kidneys filter blood to remove urea and maintain homeostasis; a decline in kidney function results in an increase in BUN.
Body mass index (BMI): A calculation utilized to correct weight changes for height and is a direct calculation regardless of gender. It is the result of the weight in kilograms divided by the height in meters squared. If nonmetric measurements are used, it is the result of the weight in pounds multiplied by 703 and then that quantity divided by the product of height in inches squared.
Bone and mineral disorders (BMMD): Altered bone turnover that results from sustained metabolic conditions that occur in chronic kidney disease, including secondary hyperparathyroidism, hyperphosphatemia, hypocalcemia, and vitamin D deficiency. The disease can be characterized by high bone turnover, low bone turnover or adynamic disease, or may be a mixed disorder.
Bone remodeling: The constant process of bone turnover involving bone resorption followed by bone formation.
Bouchard’s nodes: Hard, bony enlargement of the proximal interphalangeal (middle) joint of a finger or toe.
Brachial plexus: Collection of nerves that arises from the spine at the base of the neck from nerves that supply parts of the shoulder, arm, forearm, and hand.
Brachytherapy: A procedure in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called internal radiation, implant radiation, or interstitial radiation therapy.
Bradykinesia: Slow movement.
Breakpoint: The concentration of the antimicrobial agent that can be achieved in serum after a normal or standard dose of that antimicrobial agent.
Bronchiectasis: Chronic condition of one or more bronchi or bronchioles marked by irreversible dilatation and destruction of the bronchial walls.
Bronchoalveolar lavage: Washing out of the lungs with saline or mucolytic agents for diagnostic or therapeutic purposes.
Bronchoscopy: An examination used for inspection of the interior of the tracheobronchial tree.
Bullectomy: Surgical removal of one or more bullae (air spaces in the lung measuring more than 1 cm in diameter in the distended state).
Bursitis: An inflammation of the bursa, the fluid-filled sac near the joint where tendons and muscles pass over bone.
Cachectic: Physical wasting with loss of weight and muscle mass caused by cancer.
Cachexia: Weight loss, wasting of muscle, loss of appetite, and general debility that can occur with cancer. Anorexia may or may not be present.
CAM (abbreviation of “complementary and alternative medicines”): Defined as “dietary supplements” by the FDA; are not considered as “drugs” and therefore are not regulated as drugs.
Capillary leak: Loss of intravascular volume into the interstitial space within the body.
Carcinoembryonic antigen (CEA): A protein normally seen during fetal development. When elevated in adults it suggests the presence of colorectal and other cancers. Normal range is less than 2.5 ng/mL (less than 2.5 mcg/L) in nonsmokers but can be elevated in smokers and other nonmalignant conditions such as pancreatitis.
Carcinogenesis: Production or origin of cancer.
Carcinoma: A malignant growth that arises from epithelium, found in skin or the lining of body organs. Carcinomas tend to infiltrate into adjacent tissue and spread to distant organs.
Carcinoma in situ: The cancer is limited to the epithelial cells of origin; it has not yet invaded the basement membrane.
Carcinomatosis: Condition of having widespread dissemination of carcinoma (cancer) in the body.
Cardiac cachexia: Physical wasting with loss of weight and muscle mass caused by cardiac disease. A wasting syndrome that causes weakness and a loss of weight, fat, and muscle.
Cardiac index: Cardiac output normalized for body surface area (cardiac index = cardiac output/body surface area).
Cardiac output: The volume of blood ejected from the left side of the heart per unit of time [cardiac output (L/min) = stroke volume × heart rate].
Cardiac remodeling: Genome expression resulting in molecular, cellular, and interstitial changes and manifested clinically as changes in size, shape, and function of the heart resulting from cardiac load or injury.
Carotid: The two main arteries in the neck.
Carotid bruit: Abnormal sound heard when auscultating a carotid artery caused by turbulent blood flow usually due to the presence of atherosclerotic plaques.
Carotid intima-media thickness: A measurement of the surface between the intima and media. This is a well-validated measure of the progression of atherosclerosis. Increasing measurements over time correlates with increasing atherosclerosis, whereas a decrease in the measurement is indicative of atherosclerotic regression.
Cataplexy: A sudden loss of muscle control with retention of clear consciousness that follows a strong emotional stimulus (as elation, surprise, or anger) and is a characteristic symptom of narcolepsy.
Causalgia: Persistent burning pain, allodynia, and hyperpathia following a traumatic nerve lesion.
Central pain: Pain that results from a lesion in or dysfunction of the central nervous system.
Cephalalgia: A term for head pain similar to headache.
Cervicitis: Inflammation of the cervix.
Chemoprevention: The use of drugs, vitamins, or other agents to reduce the risk, delay the development, or prevent the recurrence of cancer.
Chemoreceptor trigger zone (CTZ): Located in the area postrema of the fourth ventricle of the brain; it is exposed to cerebrospinal fluid and blood and is easily stimulated by circulating toxins to induce nausea and vomiting.
Chemosis: Edema of the conjunctiva.
Cheyne-Stokes respiration: Pattern of breathing with gradual increase in depth and sometimes in rate to a maximum, followed by a decrease resulting in apnea. The cycles ordinarily are 30 seconds to 2 minutes in duration, with 5 to 30 seconds of apnea.
Chimeric: Composed of parts from different origins.
Chloasma: Melasma characterized by irregularly shaped brown patches on the face and other areas of the skin, often seen during pregnancy or associated with the use of oral contraceptives.
Chlorpromazine equivalents: Dose of a first-generation antipsychotic approximately equivalent to 100 mg of chlorpromazine (relative potency).
Cholecystitis: Inflammation of the gallbladder.
Cholelithiasis: Also known as gallstones. Hard masses formed in the gallbladder or its passages that can block bile blow and cause severe upper right quadrant abdominal pain (sometimes radiating to the right shoulder).
Cholestasis: Reduced or lack of flow of bile, or obstruction of bile flow.
Cholesteatoma: A mass of keratinized epithelial cells and cholesterol resembling a tumor that forms in the middle ear or mastoid region.
Chorea: A type of dyskinesia with rhythmic dance-like movement. The increase in motor activity may be associated with fidgetiness, twitching, or flinging movements.
Chronic disorder: An acid–base disturbance that has been present for hours to days.
Chronic kidney disease (CKD): A progressive, irreversible decline in kidney function that occurs over a period of several months to years.
Chronic stable angina: Manifestation of ischemic heart disease (IHD) that typically results when an atherosclerotic plaque progresses to occlude at least 70% of a major coronary artery. Patients typically present with a sensation of chest pressure or heaviness that is evoked by exertion and relieved with rest or sublingual nitroglycerin.
Chronotropic: Referring to changes in the heart rate.
Chvostek’s sign: Noted when a tap on the patient’s facial nerve adjacent to the ear produces a brief contraction of the upper lip, nose, or side of the face.
Chylothorax: The presence of lymphatic fluid (chyle) in the pleural cavity.
Circadian: Events that occur over a 24-hour interval.
Circadian rhythm: 24-Hour cycles of behavior and physiology that are generated by endogenous biological clocks (pacemakers).
Circulatory shock: A condition wherein the circulatory system is inadequately supplying the oxygen and vital metabolic substrates to cells throughout the body.
Cirrhosis: Hepatic fibrosis and regenerative nodules that have destroyed the architecture of the liver, scarring the liver tissues.
Clinical cure: Resolution of signs and symptoms of a disease.
Clonal expansion: An immunological response in which lymphocytes stimulated by antigen proliferate and amplify the population of relevant cells.
Closed comedo: A plugged follicle of sebum, keratinocytes, and bacteria that remains beneath the surface of the skin. Also referred to as a “whitehead.”
Clotting cascade: A series of enzymatic reactions by clotting factors leading to the formation of a blood clot. The clotting cascade is initiated by several thrombogenic substances. Each reaction in the cascade is triggered by the preceding one and the effect is amplified by positive feedback loops.
Clotting factor: Plasma proteins found in the blood that are essential to the formation of blood clots. Clotting factors circulate in inactive forms but are activated by their predecessor in the clotting cascade or a thrombogenic substance. Each clotting factor is designated by a roman numeral, e.g., Factor VII, and by the letter “a” when activated, e.g., Factor VIIa.
Clubbing: A deformity produced by proliferation of the soft tissues at the terminal phalanges of the fingers or toes.
CMV disease: This is the term used when patients who are already infected with cytomegalovirus (CMV) present with the classically associated symptoms that resemble a viral infection and may include fever, malaise, arthralgias, and others.
CMV infection: This is the term used when a patient has anti-CMV antibodies in the blood, when CMV antigens are detected in infected cells, or when the virus is isolated from a culture.
Coalescence: Fusion of smaller lipid emulsion particles forming larger particles, resulting in destabilization of the emulsion.
Cognitive function: Executive function and mental processing such as understanding, perception, reasoning, language, and awareness. Executive function involves a long list of skills, which can be divided into four categories: organization, self-regulation, attention, and problem solving. For example, a patient may have trouble thinking quickly, making decisions, planning, and prioritizing tasks. These functions can be evaluated by various neuropsychological tests.
Coitus: Sexual intercourse.
Collateral damage: The development of resistance occurring in a patient’s nontargeted flora that can cause secondary infections.
Colloids: Intravenous fluids composed of water and large-molecular weight molecules used to increase volume in patients with hypovolemic shock via increased intravascular oncotic pressure.
Colon cancer: A disease in which cells in the lining of the colon become malignant (cancer) and proliferate without control. Often referred to as colorectal cancer to include cancer cells found in the rectum.
Colonoscopy: A visual examination of the colon using a lighted, lens-equipped, flexible tube (colonoscope) inserted into the rectum.
Colony forming units: The number of microorganisms that form colonies when cultured and is indicative of the number of viable microorganisms in a sample.
Comedolytic: An agent that is able to break up or destroy a comedo.
Comorbidities: Multiple disease states occurring concurrently in one patient.
Compartment syndrome: The compression of nerves and blood vessels within an enclosed space.
Complex regimen: Taking medications three or more times per day, or 12 or more doses per day.
Complicated disorder: The presence of two or more distinct disorders.
Computed tomography: Radiographic imaging of anatomic information from a cross-sectional plane of the body.
Concreteness: Inability to think in abstract terms. It may be a primary developmental defect or secondary to organic mental disorder or schizophrenia.
Congenital adrenal hyperplasia: A rare inherited condition resulting from a deficiency in cortisol and aldosterone synthesis with resulting excess androgen production. The clinical presentation depends on the variant of the condition but typically manifests as abnormalities in sexual development and/or adrenal insufficiency.
Conidia: Propagating form (spores) of filamentous fungi that are released into soil and air currents. Inhalation of spores is the most common route of infections for endemic fungi and invasive molds.
Conjunctival injection: Erythema of the conjunctiva.
Conjunctivitis: Inflammation of the conjunctiva.
Conjunctivitis medicamentosa: A contact allergy to a topical medication.
Consolidation: A type of high-dose chemotherapy given as the second phase (after induction) of a treatment regimen for leukemia.
Contiguous: Describes two structures that are in close contact, or located next to each other.
Continuous positive airway pressure (CPAP): Therapy delivered using a nasal mask to improve the patency of the upper airway by maintaining sufficient air pressure to alleviate sleep-disordered breathing.
Contralateral: Pertaining to the opposite side of the body.
Convection: The movement of dissolved solutes across a semipermeable membrane by applying a pressure gradient to the fluid transport.
Convulsion: A violent involuntary contraction or series of contractions of voluntary muscles.
Copulation: Sexual union of male and female; coitus; sexual intercourse. Also, conjugation between two cells that do not fuse but separate after mutual fertilization.
Corneal arcus: Accumulation of lipid on the cornea.
Coronary Artery Bypass Graft (CABG) Surgery: Thoracic surgery where parts of a saphenous vein from a leg or internal mammary artery from the arm are placed as conduits to restore blood flow between the aorta and one or more coronary arteries to “bypass” the coronary artery stenosis (occlusion).
Coronary heart disease (CHD): Narrowing of one or more of the major coronary arteries, most commonly by atherosclerotic plaques. Also referred to as coronary artery disease.
Cor pulmonale: Right-sided heart failure, usually due to structural lung disease, e.g., pulmonary fibrosis, emphysema.
Corpus luteum: The small yellow endocrine structure that develops within a ruptured ovarian follicle and secretes progesterone and estrogen.
Corticotropin-releasing hormone: A hormone released by the hypothalamus that stimulates release of adrenocorticotropic hormone by the anterior pituitary gland.
Cortisol: An adrenal gland hormone responsible for maintaining homeostasis of carbohydrate, protein, and fat metabolism.
Cosyntropin: A synthetic version of adrenocorticotropic hormone.
Counterirritant: A substance that elicits a superficial inflammatory response with the objective of reducing inflammation in deeper, adjacent structures.
C-peptide levels: A peptide which is made when proinsulin is split into insulin and C-peptide. They split before proinsulin is released from endocytic vesicles within the pancreas—one C-peptide for each insulin molecule. C-peptide is the abbreviation for “connecting peptide.” It is used to determine if a patient has type 1 or type 2 diabetes mellitus.
Creaming: Aggregation of lipid emulsion particles that then migrate to the surface of the emulsion; can be reversed with mild agitation.
Creatine kinase, Creatine kinase myocardial band: Creatine kinase (CK) enzymes are found in many isoforms, with varying concentrations depending on the type of tissue. CK is a general term used to describe the nonspecific total release of all types of CK, including that found in skeletal muscle (MM), brain (BB), and heart (MB). CK MB is released into the blood from necrotic myocytes in response to infarction and is a useful laboratory test for diagnosing myocardial infarction. If the total CK is elevated, then the relative index (RI), or fraction of the total that is composed of CK MB, is calculated as follows: RI equal to (CK MB/CK total) × 100. An RI greater than 2 is typically diagnostic of infarction.
Creatinine: A waste product in the blood produced from the breakdown of protein by-products generated by muscle in the body or ingested in the diet. The kidneys filter blood to remove creatinine and maintain homeostasis. A decline in kidney function results in an increase in creatinine.
Creatinine clearance: Rate at which creatinine is filtered across the glomerulus; estimate of glomerular filtration rate.
Cretinism: Obsolete term for congenital hypothyroidism.
Cross allergenicity: Sensitivity to one drug and then reacting to a different drug with a similar chemical structure.
CRP (C-reactive protein): A globulin produced by the liver that appears in the blood in certain acute inflammatory conditions, such as rheumatic fever and bacterial infections.
Crypt abscess: Neutrophilic infiltration of the intestinal glands (crypts of Lieberkuhn). A characteristic finding in patients with ulcerative colitis.
Crystalloids: Intravenous fluids composed of water and electrolytes, e.g., sodium, chloride, etc., used as intravascular volume expanders for patients with hypovolemic shock.
Culture-negative IE: Implies acute endocardial damage with negative blood cultures. It is common in patients treated with antibiotics before blood cultures are obtained.
Cutis laxis: Hyperflaccidity of the skin with loss of elasticity.
Cyanosis: Bluish discoloration of the skin and mucous membranes due to lack of oxygenation.
Cyclic citrullinated peptide (CCP): A circular peptide (a ring of amino acids) containing the amino acid citrulline. Autoantibodies directed against CCP provide the basis for a test of importance in rheumatoid arthritis.
Cyclooxygenase: An enzyme that catalyzes the conversion of arachidonic acid to prostaglandins and consists of two isoforms, generally referred to as COX-1 and COX-2.
Cystitis: Inflammation of urinary bladder.
Cyst: An abnormal membranous sac within the body that contains liquid or partially solid material.
Cystocele: Hernial protrusion of the bladder, usually through the vaginal wall.
Cytogenetic analysis: Laboratory identification of chromosomes that looks for mutational defects.
Cytokine: Regulatory proteins, such as interleukins and lymphokines, that are released by cells of the immune system and act as intercellular mediators in the generation of an immune response.
Dactylitis (“hand-foot syndrome”): Diffuse swelling of the hands and or feet often associated with pain and tenderness.
Deep vein thrombosis: A disorder of thrombus formation causing obstruction of a deep vein in the leg, pelvis, or abdomen.
Deescalation: Decreasing antimicrobial regimen spectrum of activity to provide coverage against specific antimicrobial-sensitive pathogens recovered from culture.
Delirium: Transient brain syndrome presenting as disordered attention, cognition, psychomotor behavior, and perception.
Dementia: An organic mental disorder characterized by a general loss of intellectual abilities involving impairment of memory, judgment, and abstract thinking as well as changes in personality.
Denervation: Loss of nerve impulse input, e.g., by severing a nerve during surgery or nerve impulse blockade farther up the nerve chain.
Dennie-Morgan line: A line or fold below the lower eyelids associated with atopy.
Dermatophytes: Any microscopic fungus that grows on the skin, scalp, nails, or mucosa but does not invade deeper tissues.
Desensitization: A method to reduce or eliminate an individual’s negative reaction to a substance or stimulus.
Desquamation: Peeling or shedding of the epidermis (superficial layer of the skin) in scales or flakes.
Detumescence: The return of the penis to a flaccid state.
Diabetes insipidus: Polyuria due to the failure of renal tubules to reabsorb water in response to antidiuretic hormone.
Diabetic ketoacidosis: A reversible but life-threatening short-term complication primarily seen in patients with type 1 diabetes caused by the relative or absolute lack of insulin that results in marked ketosis and acidosis.
Dialysate: The physiologic solution used during dialysis to remove excess fluids and waste products from the blood.
Dialysis: The process of removing fluid and waste products from the blood across a semipermeable membrane to maintain fluid, electrolyte, and acid–base balance in patients with kidney failure.
Diaphoretic (diaphoresis): Sweating profusely.
Diarrhea: Loose, watery stools occurring more than three times in 1 day.
Diarthrodial joint: A freely moveable joint, e.g., knee, shoulder. Contrast with amphiarthrodial joint (a slightly movable joint, e.g., vertebral joint) and synarthrodial joint (an unmovable joint, e.g., fibrous joint).
Diastolic dysfunction: Abnormal filling of the ventricles during diastole.
Diphasic dyskinesia: Motor fluctuations occur while the plasma levodopa concentrations are rising and when they are falling. In each dosing interval, the patient may experience improvement, dyskinesia, and improvement (IDI) or dyskinesia, improvement, and dyskinesia (DID).
2,3-Diphosphoglycerate: A compound in red blood cells that affects oxygen binding to and release from hemoglobin.
Direct current cardioversion: The process of administering a synchronized electrical shock to the chest, the purpose of which is to simultaneously depolarize all of the myocardial cells, resulting in restoration of normal sinus rhythm.
Disease-free survival: Length of time after treatment during which no disease is found.
Disk diffusion test (D-test): A test performed in the microbiology laboratory to detect antibiotic sensitivity in bacteria.
Disseminated idiopathic skeletal hyperostosis (DISH): Excessive bone formation at skeletal sites subject to stress, generally where tendons and ligaments attach to bone.
DNA mismatch repair genes: Genes that identify and correct errors in DNA base pairs during DNA replication. Mutations in the genes can lead to cancer by allowing abnormal cells to continue to grow.
Dose intensity: Delivery of a predetermined dose per unit of time, i.e., mg/m2/week.
Downregulation: The process of reducing or suppressing a response to a stimulus.
Drusen: Tiny yellow or white deposits of extracellular material in the eye.
Ductus arteriosus: Shunt connecting the pulmonary artery to the aortic arch that allows most of the blood from the right ventricle to bypass the fetus lungs.
Duodenal: The first of three parts of the small intestine.
Dysarthria: Difficult or defective speech, usually due to impairment of tongue movement or of other muscles essential to speech.
Dysentery: An illness involving severe diarrhea that is often associated with blood in the stool.
Dysesthesia: An unpleasant abnormal sensation.
Dysgeusia: Unpleasant taste in the mouth.
Dyskinesia: Abnormal involuntary movements, which include dystonia, chorea, and akathisia.
Dyslipidemia: Elevation of the total cholesterol, low-density lipoprotein cholesterol or triglyceride concentrations, or a decrease in high-density lipoprotein cholesterol concentration in the blood.
Dysmenorrhea: Crampy pelvic pain occurring with or just prior to menses. “Primary” dysmenorrhea implies pain in the setting of normal pelvic anatomy, while “secondary” dysmenorrhea is secondary to underlying pelvic pathology.
Dyspareunia: Pain during or after sexual intercourse.
Dysphagia: Painful or difficult swallowing, accompanied by a sensation of food being stuck in passage.
Dysphasic: An alteration in normal speech patterns or content.
Dysphonia: Impairment of the voice or difficulty speaking.
Dysphoria: A general mood of depression, dissatisfaction, and unrest.
Dyspnea: Shortness of breath or difficulty breathing.
Dyssynergic defecation: A lack of coordination between the pelvic floor muscles and the anal sphincter.
Dystonia: A type of dyskinesia. Movement is slow and twisting. It may be associated with painful muscle contractions or spasms.
Dysuria: Difficulty or pain related to urination
Ebstein’s anomaly: Congenital heart defect in which the opening of the tricuspid valve is displaced toward the apex of the right ventricle of the heart.
Eburnation: A condition in which bone or cartilage becomes hardened and denser.
Ecchymoses: Passage of blood from ruptured blood vessels into subcutaneous tissue causing purple discoloration of the skin.
Ectopic pregnancy: Presence of a fertilized ovum outside of the uterine cavity.
Effector cells: Cells that become active in response to initiation of the immune response.
Ejection fraction: The fraction of the volume present at the end of diastole that is pushed into the aorta during systole.
Electrocardiogram: A noninvasive recording of the electrical activity of the heart.
Electroconvulsive therapy: Administration of electric current to the brain through electrodes placed on the head in order to induce seizure activity in the brain, used in the treatment of certain mental disorders.
Electroencephalogram (EEG): A recording of patterns of electrical impulses in the brain.
Electroencephalography: The recording of brain waves via electrodes placed on the scalp or cortex.
Embolectomy: Surgical removal of a clot or embolism.
Embolism: Sudden blockage of a vessel caused by a blood clot or foreign material which has been brought to the site by the flow of blood.
Embolization: The process by which a blood clot or foreign material dislodges from its site of origin, flows in the blood, and blocks a distant vessel.
Emesis: See vomiting.
End-stage liver disease: Liver failure that is usually accompanied by complications such as ascites or hepatic encephalopathy.
Endarterectomy: Removal of a thrombus from the carotid artery.
Endemic fungi: Fungi that are native or prevalent to a particular area or region.
Endocinch: An endoscopic sewing technique used to improve lower esophageal sphincter tone.
Endometritis: Inflammation of the endometrium.
Endoscopic evaluation: General term used to describe the visual inspection of the inside of hollow organs with an endoscope. Used mainly for diagnostic purposes. Refers to procedures such as gastroscopy, duodenoscopy, colonoscopy, sigmoidoscopy, and others.
Endoscopic retrograde cholangiopancreatography (ERCP): A technique in which an endoscope is passed through the mouth and stomach to the duodenum in order to examine abnormalities of the bile ducts, pancreas, and gallbladder.
Endoscopy: A procedure used to evaluate the interior surfaces of an organ by inserting a small scope into the body through which one can directly examine almost any part of the intestinal tract. Biopsies can be obtained, polyps removed, and clear images obtained.
Endothelial cell: A single layer of cell surrounding the lumen of arteries.
Engraftment: The process by which transplanted stem cells begin to grow and reproduce in the recipient to produce functioning leukocytes, erythrocytes, and platelets.
Enteral nutrition: Delivery of nutrients via the gastrointestinal tract, either by mouth or by feeding tube.
Enterobacteriaceae: A family of enteric gram-negative bacilli, e.g., Escherichia coli or Klebsiella pneumoniae.
Enterocytes: Cells lining the small intestine.
Enuresis: Incontinence at night.
Enzyme-linked immunoabsorbent assay (ELISA): A solid phase in the form of a microtiter plate or bead to which HIV antigen is attached. The antigen may be either a preparation of lysed whole virus or a combination of recombinant viral antigens.
Epilepsy: A neurologic disorder characterized by recurring motor, sensory, or psychic malfunction with or without loss of consciousness or convulsive seizures.
Epistaxis: Nasal hemorrhage with blood drainage through the nostrils; a nosebleed.
Erectile dysfunction (ED): Condition defined as the inability to achieve or maintain an erection sufficient for sexual intercourse.
Erythema multiforme: A rash characterized by papular (small raised bump) or vesicular lesions (blisters), and reddening or discoloration of the skin often in concentric zones about the lesion.
Erythematous: Flushing of the skin caused by dilation of capillaries. Erythema is often a sign of inflammation and infection.
Erythrocyte sedimentation rate (ESR): A nonspecific inflammatory marker that may be elevated in some infections and inflammatory diseases; specifically, the ESR is obtained from a blood sample by measuring the distance that red blood cells precipitate after 1 hour.
Erythropoiesis stimulating agents (ESAs): Agents developed by recombinant DNA technology that have the same biological activity as endogenous erythropoietin to stimulate erythropoiesis (red blood cell production) in the bone marrow. The currently available agents in the United States are epoetin alfa and darbepoetin alfa.
Erythropoietin: A hormone primarily produced by the progenitor cells of the kidney that stimulates red blood cell (RBC) production in the bone marrow. Lack of this hormone leads to anemia.
Esophageal varices: Dilated blood vessels in the esophagus.
Esophagitis: Inflammation of the esophagus that occurs when the esophagus is repeatedly exposed to refluxed material for prolonged periods of time.
Essential fatty acid deficiency: Deficiency of linoleic acid, linolenic acid, and/or arachidonic acid, characterized by hair loss, thinning of skin, and skin desquamation. Long-chain fatty acids include trienes (containing three double-bonds, e.g., 5,8,11-eicosatrienoic (or Mead) acid, trienoic acids,) and tetraenes (containing four double bonds, e.g., arachidonic acid). Biochemical evidence of essential fatty acid deficiency includes a triene:tetraene greater than 0.2 and low linoleic or arachidonic acid plasma concentrations.
Euthymia: Normal mood.
Euthyroid: State of normal thyroid function or hormone activity.
Event-free survival: This term refers to the length of time after treatment that a person remains free of certain negative events.
Evoked potential testing: A procedure in which sensory nerve pathways are stimulated, and the time lapse to electrical response in the corresponding area of the brain is measured.
Exanthem: Skin eruption.
Exfoliative dermatitis: Severe inflammation of the entire skin surface due to a reaction to certain drugs.
Exophthalmos: Abnormal protrusion of the eyeball, seen in Grave’s disease.
Exploratory laparotomy: Surgical incision into the abdominal cavity, performed to examine the abdominal organs and cavity in search of an abnormality and diagnosis.
External beam radiotherapy: Treatment by radiation emitted from a source located at a distance from the body. Also called beam therapy and external beam therapy.
Extra-abdominal: Outside of the abdominal cavity.
Extraction ratio: Fraction of the drug entering the liver in the blood which is irreversibly removed.
Extrapyramidal reaction: A combination of neurologic effects which includes tremor, chorea, athetosis, and dystonia; a common side effect of antipsychotic agents.
Extrapyramidal symptoms: Adverse effects of medications such as antipsychotics. They include dystonia (involuntary muscle contractions), tardive dyskinesia (repetitive, involuntary movements), parkinsonian symptoms (akinesia, rigidity, and tremors), and akathisia (motor or subjective restlessness).
Extravasation: Movement of fluid from inside a blood vessel into the surrounding tissues.
Facultative: Biologically capable but not restricted to a particular function or mode of life, e.g., survival within macrophages.
Facultative anaerobe: An organism that makes ATP by aerobic respiration if oxygen is present, but switches to fermentation under anaerobic conditions.
Felty’s syndrome: An extra-articular manifestation of rheumatoid arthritis associated with splenomegaly and neutropenia.
Festination: Walking with short, rapid, shuffling steps.
Fibrin: An insoluble protein that is one of the principal ingredients of a blood clot. Fibrin strands bind to one another to form a fibrin mesh. The fibrin mesh often traps platelets and other blood cells.
Fibrinolysis: A normal ongoing process that dissolves fibrin and results in the removal of small blood clots; hydrolysis of fibrin.
Fibroadenoma: A benign neoplasm which commonly occurs in breast tissue and is derived from glandular epithelium.
Fibrosis: Formation of tissue containing connective tissues formed by fibroblasts as part of tissue repair or as a reactive process.
Fistula: Abnormal connection between two internal organs (e.g., arteriovenous fistula, a connection between an artery and a vein) or between an internal organ and the exterior or skin (e.g., enterocutaneous fistula, a connection between the intestine and the skin); often seen in severe cases of Crohn’s disease.
Flight of ideas: A nearly continuous flow of rapid speech and thought that jumps from topic to topic, usually loosely connected.
Floppy iris syndrome: Disorder associated with excessive relaxation of the iris dilator muscle, which results in a flaccid iris.
Flow cytometry: Technology used to study characteristics of individual cells in a suspension.
Fluorescence in situ hybridization (FISH): A laboratory technique used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye are made in the laboratory and added to cells or tissues on a glass slide. When these pieces of DNA bind to specific genes or areas of chromosomes on the slide, they light up when viewed under a microscope with a special light.
Foam cell: Lipid-laden white blood cells.
Forced expiratory volume in 1 second: The volume of air that a patient can forcibly blow out in the first second of forced exhalation after taking a maximal breath.
Forced vital capacity: The maximum volume of air that can be forcibly exhaled after taking a maximal breath.
Fragility fracture: Fracture resulting from a fall from standing height or less amount of trauma.
Frailty: Excess demand imposed upon reduced capacity; a common biological syndrome in the elderly.
Frank-Starling mechanism: One of the mechanisms by which the heart can increase cardiac output.
Freelite assay: A highly sensitive assay that determines the ratio of serum-free light chain kappa to lambda.
Friable: Easily crumbled, pulverized, or reduced to powder.
Friction: Risk factor for pressure ulcers that is created when a patient is dragged across a surface, which can lead to superficial skin damage.
Fronto-temporal: Located to the front or side of the head.
Fructooligosaccharides: Polymers of fructose that reach the colon undigested and are broken down there to short-chain fatty acids by bacterial enzymes.
Functional gastrointestinal disorder: A term used to describe symptoms occurring in the gastrointestinal tract in the absence of a demonstrated pathologic condition. The clinical product of psychosocial factors and altered intestinal physiology involving the brain–gut interrelationship.
Gadolinium: An intravenous contrast agent used with magnetic resonance imaging.
Galactorrhea: Inappropriate breast milk production and secretion.
Gallstone (cholelithiasis): A solid formation in the gallbladder or bile duct (choledocholithiasis if in the bile duct) composed of cholesterol and bile salts.
Gamma knife: A device which uses multiple converging beams of γ-radiation from cobalt-60 to highly focus radiation on small tumors within the brain.
Gastric bypass: A surgical procedure for weight loss that elicits its effectiveness through malabsorption and volume limitation. The procedure involves full partitioning of the proximal gastric segment into a jejunal loop.
Gastritis: Acute or chronic inflammation of the lining of the stomach.
Gastroenteritis: Inflammation of the gastrointestinal tract causing nausea, vomiting, diarrhea, and fever; sometimes referred to as the stomach flu although not related to influenza.
Gastroesophageal reflux disease: Troublesome symptoms and/or complications caused by refluxing the stomach contents into the esophagus. These troublesome symptoms adversely affect the well-being of the patient.
Gastroparesis: A form of autonomic neuropathy involving nerves of the stomach. It may include nausea, vomiting, feeling full, bloating, and lack of appetite. It may cause wide fluctuations in blood sugars due to insulin action and nutrient delivery not occurring at the same time.
Gastroplasty: A surgical procedure for weight loss that elicits its effectiveness through gastric volume limitation. The procedure involves partial partitioning at the proximal gastric segment with the placement of a gastric outlet stoma of fixed diameter.
Gastroschisis: Inherited congenital abdominal wall defect in which the intestines and sometimes other organs develop outside the fetal abdomen through an opening in the abdominal wall.
Gastrostomy: Operative placement of a new opening into the stomach, usually associated with feeding tube placement.
Geniculate nucleus: The portion of the brain that processes visual information from the optic nerve and relays it to the cerebral cortex.
Genotype: The genetic constitution of an individual.
Geriatric syndrome: Age-specific presentations or differential diagnoses, including visual and hearing impairment, malnutrition and weight loss, urinary incontinence, gait impairment and falls, osteoporosis, dementia, delirium, sleep problems, and pressure ulcers. Commonly seen conditions in elder patients.
Gestational diabetes: Diabetes that occurs during pregnancy which may or may not end at delivery.
Gigantism: A condition of abnormal size or overgrowth of the entire body or any of its parts. Characteristic of growth hormone excess that manifests prior to closure of epiphyseal plates.
Glasgow Coma Scale: A scale for evaluating level of consciousness after central nervous system injury (evaluates eye opening and verbal and motor responsiveness).
Glomerular filtration rate (GFR): The volume of plasma that is filtered by the glomerulus per unit time, usually expressed as mL/min or mL/min/1.73 m2, which adjusts the value for body surface area. This is the primary index used to describe overall renal function.
Glomerulonephritis: Glomerular lesions that are characterized by inflammation of the capillary loops of the glomerulus. These lesions are generally caused by immunologic, vascular, or other idiopathic diseases.
Glucagon: Hormone involved in carbohydrate metabolism that is produced by the pancreas and released when glucose levels in the blood are low. When blood glucose levels decrease, the liver converts stored glycogen into glucose, which is released into the bloodstream. The action of glucagon is opposite to that of insulin.
Gluconeogenesis: Formation of glucose from precursors other than carbohydrates especially by the liver and kidney using amino acids from proteins, glycerol from fats, or lactate produced by muscle during anaerobic glycolysis.
Glucuronidation: A metabolic pathway in the body that combines a drug (or other compound) that possesses a phenol, alcohol, or carboxyl group with glucuronic acid.
Glutamate: An excitatory amino acid found in the central nervous system.
Glycogenolysis: The process by which glycogen is broken down into glucose in body tissues.
Goiter: An enlargement of the thyroid gland, causing a swelling in the front part of the neck.
Gonioscopy: Examination of the anterior chamber angle. A gonioprism or Goldman lens is used to perform gonioscopic evaluation.
Gout: A group of disorders of purine metabolism, manifested by various combinations of (1) hyperuricemia; (2) recurrent acute inflammatory arthritis induced by crystals of monosodium urate monohydrate; (3) tophaceous deposits of these crystals in and around the joints of the extremities, which may lead to crippling destruction of joints; and (4) uric acid urolithiasis.
Graft-versus-host disease: The phenomenon by which transplanted donor T cells recognize normal host tissues as foreign and attack these tissues, resulting in increased morbidity and mortality in allogeneic transplant patients.
Graft-versus-tumor effect: The phenomenon by which transplanted donor cells recognize host malignant cells as foreign and eradicate the malignant cells through immunologic mechanisms.
Grandiosity: Exaggerated sense of self-importance, ideas, plans, or abilities.
Granulomas: Masses of chronically inflamed tissues with granulations.
Gummatous: A tumor of rubbery consistency that is characteristic of the tertiary stage of syphilis.
Gut-associated lymphoid tissue: Lymphoid tissue, including Peyer’s patches, found in the gut that are important for providing localized immunity to pathogens.
Hallucinosis: Auditory hallucinations that occur during a clear sensorium.
Haptenation: The process where a drug, usually of low molecular weight, is bound to a carrier protein or cell and becomes immunogenic.
Health literacy: Degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions.
Heberden’s nodes: Hard, bony enlargement of the distal interphalangeal (terminal) joint of a finger or toe.
Hemarthrosis: Blood in the joint space.
Hematemesis: The vomiting of blood.
Hematochezia: Passage of stool that is bright red or maroon, usually because of bleeding from the lower gastrointestinal tract.
Hematogenous: Spread through the blood.
Hematuria: Presence of blood or red blood cells in urine.
Hemiballismus: A rare movement disorder that can be life threatening. Patients with hemiballismus have a dismal prognosis, with physical exhaustion, injuries, and medical complications often leading to death.
Hemiparesis: Weakness or slight paralysis involving one side of the body.
Hemisensory deficit: Loss of sensation on one side of the body.
Hemithorax: A single side of the trunk between the neck and the abdomen in which the heart and lungs are situated.
Hemolytic uremic syndrome: A disease characterized by microangiopathic hemolytic anemia, acute renal failure, and a low platelet count (thrombocytopenia).
Hemoptysis: The expectoration of blood or blood-tinged sputum from the larynx, trachea, bronchi, or lungs.
Hemorrhagic conversion: Conversion of an ischemic stroke into a hemorrhagic stroke.
Hemostasis: Cessation of bleeding through natural (clot formation or construction of blood vessels), artificial (compression or ligation), or surgical means.
Heparin-induced thrombocytopenia: A clinical syndrome of IgG antibody production against the heparin-platelet factor 4 complex occurring in approximately 1% to 5% of patients exposed to either heparin or low-molecular-weight heparin. Heparin-induced thrombocytopenia results in excess production of thrombin, platelet aggregation, and thrombocytopenia (due to platelet clumping), often leading to venous and arterial thrombosis, amputation of extremities, and death.
Hepatic encephalopathy: Confusion and disorientation that a patient with advanced liver disease experiences due to accumulation of ammonia levels.
Hepatic steatosis: Accumulation of fat in the liver.
Hepatocellular carcinoma (HCC): Cancer of the liver.
Hepatojugular reflex: Distention of the jugular vein induced by pressure over the liver; suggestive of insufficiency of the right heart.
Hepatosplenomegaly: An enlarged liver and spleen secondary to leukemic infiltration.
Hepatotoxicity: Toxicity to the liver causing damage to liver cells.
Herniation: Protrusion of the brain through the cranial wall.
Hesitancy: Difficulty with initiating micturition.
Heterotopic: Placing a transplanted organ into an abnormal anatomic location.
Heterozygous: Having different alleles at a gene locus.
Hirsutism: Excess body hair, especially appearing on the lower abdomen, around the nipples, around the chin and upper lip, between the breasts, and on the lower back.
Histocompatibility: The examination of human leukocyte antigen (HLA) differences between a donor and a recipient in order to determine if the recipient is more likely to accept, rather than reject, a graft from that particular donor.
HIV genotype: A type of resistance testing for HIV in which a patient’s blood sample is obtained, the HIV RNA is sequenced, and mutations that may confer resistance to antiretrovirals are reported.
HIV phenotype: A type of resistance testing for HIV in which a patient’s blood sample is obtained and the patient’s HIV genes that encode for reverse transcriptase and protease are removed and placed in an HIV viral vector. This viral vector is replicated in a cell culture system with varying concentrations of antiretrovirals. A drug concentration-viral inhibition curve is developed and the concentration needed to inhibit 50% of the patient’s virus is reported. This is used to predict resistance versus susceptibility.
HIV virtual phenotype: A database of matching HIV genotypes and phenotypes is developed. When an HIV genotype for a patient is obtained, the database is used to predict the patient’s phenotype based on their actual genotype using matches that occur in the database.
Homeostenosis: Impaired capability to withstand stressors and decreased ability to maintain physiological and psychosocial homeostasis; a state commonly found in the elderly.
Homonymous: Pertaining to the same side.
Homozygous: Having identical alleles at a gene locus.
Hospice: The provision of palliative care during the last 6 months of life as defined by federal guidelines.
Hot flashes: A feeling of warmth that is commonly accompanied by skin flushing and mild to severe perspiration.
Human leukocyte antigens (HLA): Groups of genes found on the major histocompatibility complex, which contain cell-surface antigen presenting proteins. The body uses HLA to distinguish between self cells and nonself cells.
Humoral: Products secreted into the blood or body fluids.
Hydramnios: Increased amniotic fluid.
Hydronephrosis: Distention of the pelvis and kidney with urine resulting from obstruction of the ureter.
β-Hydroxybutyric acid: A ketone body that is elevated in ketosis, is synthesized in the liver from acetyl-CoA, and can be used as an energy source by the brain when blood glucose is low.
Hyperalgesia: An exaggerated intensity of pain sensation.
Hypercalcemia: Excessive amount of calcium in the blood.
Hypercalciuria: Excessive amount of calcium in the urine.
Hypercapnia: Abnormally high concentration of carbon dioxide in the blood.
Hypercoagulable state: A disorder or state of excessive or frequent thrombus formation; also known as thrombophilia.
Hyperemesis gravidarum: A rare disorder of severe and persistent nausea and vomiting during pregnancy that can result in dehydration, malnutrition, weight loss, and hospitalization.
Hyperglycemic hyperosmolar nonketotic syndrome: Severe increase in serum glucose concentration without the production of ketones, leading to an increase in serum osmolality and symptoms such as increased thirst, increased urination, weakness, fatigue, confusion, and in severe cases convulsions and/or coma.
Hyperopia: Farsightedness.
Hyperosmolar hyperglycemic state: Blood glucose levels greater than 600 mg/dL without significant ketones where extreme dehydration, insulin deficiency, hyperosmolarity, and electrolyte deficiency are common.
Hyperpathia: A painful syndrome, characterized by increased reaction to a stimulus, especially a repetitive stimulus, as well as an increased threshold.
Hyperpigmentation: A common darkening of the skin that occurs when an excess of melanin forms deposits in the skin.
Hyperplasia: An abnormal or unusual increase in the cells of a body part.
Hyperprolactinemia: A medical condition of elevated serum prolactin characterized by prolactin serum concentrations greater than 20 ng/mL (20 mcg/L) in men or 25 ng/mL (25 mcg/L) in women.
Hypersomnia: Sleeping for unusually prolonged periods of time.
Hyperthermia: An unusually high body temperature.
Hyperthyroidism: State caused by excess production of thyroid hormone.
Hypertrichosis: Excessive growth of hair.
Hypertrophy: An increase in the size of the cells in a tissue or organ.
Hyperuricemia: Elevated serum uric acid concentration, defined as a level greater than 7.0 mg/dL (416 µmol/L); it is a prerequisite for the development of gout and may lead to renal disease.
Hypervigilance: The state of being extremely alert and watchful, possibly to avoid danger or harm.
Hypochlorhydria: Hypoacidity. Decreased hydrochloric acid secretion by the stomach.
Hypocretin: A wake-promoting hypothalamic neuropeptide whose deficiency is involved in the pathophysiology of narcolepsy.
Hypogammaglobinemia: Reduced levels of antibodies.
Hypogonadism: A syndrome associated with testosterone deficiency resulting from either testicular or pituitary/hypothalamic diseases. Presenting symptoms differ according to the timing of disease onset in relation to puberty.
Hypomania: Abnormal mood elevation that does not meet criteria for mania.
Hypopituitarism: A clinical disorder characterized by complete or partial deficiency in pituitary hormone production.
Hypothalamic-pituitary-adrenal axis: A neuroendocrine feedback loop that controls response to stress.
Hypothermia: An unusually low body temperature.
Hypothyroidism: State caused by inadequate production of thyroid hormone.
Hypovolemic shock: Circulatory shock caused by severe loss of blood volume and/or body water.
Hypoxemia: Deficiency of oxygen in the blood.
Hypoxia: Deficiency of oxygen.
Hysterectomy: Excision of the uterus.
Immunocompromised: A condition in which the immune system is not functioning normally. This condition is seen in very young, very old, HIV infected individuals, or in transplant patients.
Immunogenicity: The property that gives a substance the ability to provoke an immune response.
Immunoglobulin G index: The ratio of immunoglobulin G to protein in the serum or cerebrospinal fluid.
Immunophenotype: The process of identification and quantitation of cellular antigens through fluorochrome-labeled monoclonal antibodies.
Immunotherapy: Treatment of a disease by stimulating the body’s own immune system.
Impedance monitoring: A diagnostic technique used to evaluate esophageal bolus transit. When combined with pH monitoring, impedance monitoring helps identify both acidic and weakly acidic reflux episodes.
Implantable cardioverter-defibrillator: A device implanted into the heart transvenously with a generator implanted subcutaneously in the pectoral area that provides internal electrical cardioversion of ventricular tachycardia or defibrillation of ventricular fibrillation.
Incretin effect: A greater insulin stimulatory effect after an oral glucose load than that caused by an intravenous glucose infusion. The majority of the effect is thought to be due to glucose-dependent insulinotropic peptide (GIP) and glucagon like peptide-1 (GLP-1). Patients with type 2 diabetes have a significant reduction of the incretin effect, implying that these patients either have decreased concentration of the incretin hormones, or a resistance to their effects. GLP-1 concentrations are reduced in patients with type 2 diabetes in response to a meal, while GIP concentrations are either normal or increased, suggesting a resistance to the actions of GIP, thus making GLP-1 a more logical target for therapeutic intervention.
Index patient: The patient originally diagnosed with a disease.
Indirect immunofluorescence assay (IFA): HIV-infected T-lymphocytes are fixed onto a microscope slide, covered with the blood sample to be tested, incubated under heat, and washed. If antibodies to HIV are bound to the fixed viral antigens, they will remain on the slide. FITC-conjugated antihuman globulin is then added, incubated, and washed. If the sample contains antibodies to HIV, the cells will show a bright, fluorescent membrane under the microscope.
Induction: Treatment designed to be used as the first step in eliminating the leukemic burden.
Infarction: The formation of an infarct, an area of tissue death due to a local lack of oxygen.
Infective endocarditis (IE): Historically referred to as bacterial endocarditis, IE is an infection, either acute or subacute, that primarily affects the heart valves, but may extend into other surrounding areas of the heart.
Inotropic: Pertaining to the force of contraction of the heart muscle, or relating to or influencing the force of muscular contractions.
Insulin-like growth factor-I: An anabolic peptide that acts as a direct stimulator of cell proliferation and growth in all body cells.
Insulin resistance: A decreased response to insulin found before or early in the diagnosis of type 2 diabetes mellitus.
International normalized ratio (INR): The ratio of the patient’s clotting time to the clinical laboratory’s mean reference value; normalized by raising it to the international sensitivity index (ISI) power to account for differences in thromboplastin reagents. Thus, INR = (patient’s prothrombin time/laboratory’s mean normal prothrombin time)ISI.
Intima: The inner layer of the wall of an artery or vein.
Intra-abdominal: Within the abdominal cavity.
Intra-articular: Administered to or occurring in the space within joints.
Intraperitoneal: Within the peritoneal cavity.
Intrathecal: Within the meninges of the spinal cord.
Intravesicular: Administration directly into the bladder through the urethra.
Intussusception: Infolding, like the closing of a telescope, of a segment of the small intestine into the adjacent but more distal segment of the intestine, reducing blood supply to the affected part of the intestine and eventually causing intestinal obstruction.
Iontophoresis: Introduction of a medication into tissue through use of an electric current.
Ipsilateral: Pertaining to the same side of the body.
Ischemic heart disease (IHD): Imbalance between myocardial oxygen supply and oxygen demand.
Jejunal: A section of the small intestine connecting the duodenum to the ileum.
Jejunostomy: Operative placement of a new opening into the jejunum, usually associated with feeding tube placement.
Kegel exercises: Specific exercises that strengthen the pelvic floor muscles and help to prevent and treat stress incontinence.
Keratinization: The sloughing of epithelial cells in the hair follicle.
Keratinocyte: The epidermal cell that synthesizes keratin; making up 95% of all epidermal cells; commonly called “skin cells.”
Keratitis: Infection of the cornea.
Keratoconjunctivitis sicca: Also known as Sjogren’s syndrome or dry eye syndrome.
Keratotic: Pertaining to any horny growth such as a wart or callus.
Ketosis: An abnormal increase of ketone bodies present in conditions of reduced or disturbed carbohydrate metabolism.
Kindling: Repeated application of electrical stimulation to specific areas of the brain that leads to an alteration in the seizure threshold and the development of epilepsy. This process is used only in animal experimental models, but a similar phenomenon is thought to occur in humans.
Koebner’s phenomenon: The occurrence of psoriatic lesions due to skin trauma.
Korotkoff sounds: The noise heard over an artery by auscultation when pressure over the artery is reduced below the systolic arterial pressure.
Korsakoff’s syndrome: May occur as a sequel to chronic alcohol use. Characterized by psychosis, polyneuritis, disorientation, insomnia, delirium, hallucinations. Bilateral foot or wrist drop may also occur, possibly accompanied by pain.
Kyphosis: Abnormal curvature of the spine resulting in protrusion of the upper back; hunchback.
Lacrimation: Tearing and discharge of tears from the eyes.
β-Lactam allergy: Allergy to the β-lactam family, namely penicillins and cephalosporins, but may also include carbapenems.
Lactose intolerance: An inability to digest milk and some dairy products, resulting in abnormal bloating, cramping, and diarrhea; caused by enzymatic lactase deficiency.
Lag-ophthalmos: Poor closure of the upper eyelid.
Lamina cribrosa: A series of perforated sheets of connective tissue that the optic nerve passes through as it exits the eye.
Laminectomy: Excision of the posterior arch of a vertebra to relieve pressure on the spinal cord.
Laparoscopic: Abdominal exploration or surgery employing a type of endoscope called laparoscope.
Laparotomy: Surgical opening of the abdominal cavity.
Latent autoimmune diabetes in adults (LADA): A slow, progressive form of type 1 diabetes mellitus in which a patient does not require insulin for a number of years. In its early stages, LADA typically presents as type 2 diabetes mellitus and is often misdiagnosed as such. However, LADA more closely resembles type 1 diabetes mellitus and shares common physiological characteristics of type 1 diabetes mellitus for metabolic dysfunction, genetics, and autoimmune features. LADA does not affect children and is classified distinctly as being separate from juvenile diabetes.
Lentigines: Plural of lentigo. A small, flat, tan to dark brown or black, macular melanosis on the skin, which looks like a freckle but is histologically distinct. Lentigines do not darken on exposure to sunlight, freckles do.
Leukemoid reaction: An elevated white blood cell count, or leukocytosis, that is a physiologic response to stress or infection (as opposed to a primary blood malignancy, such as leukemia).
Leukocytoclastic: The breaking up of white blood cells.
Leukopenia: A condition where the number of circulating white blood cells are abnormally low due to decreased production of new cells, possibly in conjunction with medication toxicities.
Leukostasis: An abnormal intravascular leukocyte aggregation and clumping seen in leukemia patients. The brain and the lungs are the two most frequent organs involved.
Lewy bodies: Abnormal masses inside some nerve cells. They occur in a variety of locations, and their structure and composition vary depending on location.
Lhermitte’s sign: Tingling or shock-like sensation passing down the arms or trunk when the neck is flexed.
Libido: Conscious or unconscious sexual desire.
Ligament of Treitz: Landmark in the proximal portion of the jejunum beyond which it is preferred that postpyloric feedings be delivered for minimization of aspiration.
Linear accelerator: A device that uses microwave technology to accelerate electrons in a highly focused beam to deliver targeted radiation to tumor sites.
Lipase: Any one of a group of lipolytic enzymes that cleave a fatty acid residue from the glycerol residue in a neutral fat or a phospholipid.
Lipophilic: Having an affinity for fatty substances.
Lipoprotein lipase: Enzyme located in the capillary endothelium involved in the breakdown of intravenous lipid emulsion particles.
Liver biopsy: A procedure whereby tissue is removed from the liver and is used to determine the severity of liver damage.
Locus ceruleus: Nucleus of norepinephrine containing neurons located in the brainstem which is responsible for physiologic response to stress and panic.
Luteolysis: Death of the corpus luteum.
Lymphadenectomy: Surgical excision of lymph nodes.
Lymphadenitis: Inflammation of the lymph nodes, which become swollen, painful, and tender.
Lymphangitis: Inflammation of lymphatic channels.
Lymphatic: The network of vessels carrying tissue fluids.
Lymphoproliferative: Of or related to the growth of lymphoid tissue.
Maceration: The softening or breaking down of a solid by leaving it immersed in a liquid.
Macrophages: A large scavenger cell.
Macrovascular complications: Vascular complications that are contributed to by diabetes and include heart attacks, strokes, or peripheral vascular disease.
Macula: The central portion of the retina.
Maculopapular: A rash that contains both macules and papules. A macule is a flat discolored area of the skin, and a papule is a small raised bump. A maculopapular rash is usually a large area that is red and has small confluent bumps.
Magnetic resonance imaging: Method of body imaging that uses a magnetic field and radio waves to create cross-sectional images of one’s body, which provides detailed pictures of organs and tissues.
Major malformation: A defect that has either cosmetic or functional significance.
Mastalgia: Tenderness of the breast.
Matrix metalloproteinases: Enzymes responsible for the degradation of connective tissue, normally located in the extracellular space of tissue, that break down proteins (e.g., collagen) and require zinc or calcium atoms as cofactors for enzymatic activity.
Meconium: The first intestinal discharge or “stool” of a newborn infant, usually green in color and consisting of epithelial cells, mucus, and bile.
Media: The middle layer of the wall of an artery or vein.
Mediastinum: The space in the thoracic cavity between the pleural sacs and behind the sternum.
Melanosis: Excessive pigmentation of the skin due to a disturbance in melanin pigmentation; called also melanism.
Melasma: Patchy skin pigmentation, often seen during pregnancy.
Melena: Tarry stools.
Menarche: The onset of cyclic menstrual periods in a woman.
Meningeal: Membranes that surround the brain and spinal cord.
Meninges: Covering of the brain consisting of three layers.
Menopause: Permanent cessation of menstruation.
Menorrhagia: Menstrual blood loss of greater than 80 mL per cycle; a more practical definition is heavy menstrual flow associated with problems of containment of flow, unpredictably heavy flow days, or other associated symptoms.
Mesocortical: A neural pathway that connects the ventral tegmentum to the cortex, particularly the frontal lobes. It is one of the major dopamine pathways in the brain.
Mesocorticolimbic pathway: A neural pathway that loops between the midbrain, the cortex, and limbic areas of the brain. An integral part of the brain reward system.
Mesothelioma: A benign or malignant tumor affecting the lining of the chest or abdomen. Commonly caused by exposure to asbestos fibers.
Metabolic acidosis: A condition in the blood and tissues that is a consequence of an accumulation of lactic acid resulting from tissue hypoxia and anaerobic metabolism.
Metabolic alkalosis: Alkalosis that is caused by an increase in the concentration of alkaline compounds (typically bicarbonate).
Metabolic syndrome: Constellation of cardiovascular risk factors related to hypertension, abdominal obesity, dyslipidemia, and insulin resistance diagnosed by the presence of at least three of the following criteria: increased waist circumference, elevated triglyceride concentrations, decreased high-density lipoprotein (HDL) cholesterol or active treatment to raise HDL cholesterol, elevated blood pressure or active treatment with antihypertensive therapy, or elevated fasting glucose or active treatment for diabetes.
Metastasis: Pleural is metastases. Cancer that has spread from the original site of the tumor.
Micelle: A microscopic particle of digested fat and cholesterol.
Microalbuminuria: Loss of small amounts of protein in the urine. An albumin excretion ratio of 30 to 300 mg/24 hour, which is a sign of chronic kidney disease. The normal mean value for urine albumin excretion in adults is 10 mg/day.
Microdialysis: A brain research technique whereby very small probes are inserted into the brain, and the concentration of brain chemicals, such as neurotransmitters, can be measured.
β2 Microglobulin: A low-molecular-weight protein that may be elevated in multiple myeloma.
Micrognathia: Abnormal smallness of the jaws, especially of the mandible.
Microvascular complications: Vascular complications contributed to by diabetes that include retinopathy, neuropathy, and nephropathy.
Microvascular pulmonary emboli: An obstruction in the small blood vessels in the lung caused by material (e.g., blood clot, fat, air, and foreign body) that is carried through the circulation until it lodges in another small vessel.
Micturition: Voiding, urination.
Migraineur: A person who suffers from migraine headaches.
Migrographia: Small handwriting, often seen in patients with Parkinson’s disease.
Minimal residual disease: A quantitative assessment of sub-clinical remnant of leukemic burden remaining at the end of the initial phase of treatment (induction) when a patient may appear to be in a complete morphologic remission.
Minimum inhibitory concentration: The lowest concentration of an antimicrobial agent that inhibits visible bacterial growth after approximately 24 hours.
Minor malformation: A defect that occurs infrequently (less than 4% of the population) but that has neither cosmetic nor functional significance to the child.
Miosis: Pupillary constriction, “pinpoint” pupils.
Mitogenicity: Producing or stimulating mitosis (a process that takes place in the nucleus of a dividing cell resulting in the formation of two new nuclei, each having the same number of chromosomes as the parent nucleus).
Mixed disorder: The presence of two or more distinct disorders. See also Complicated disorder.
Mixed mood episodes: Symptoms of mania and depression occurring simultaneously or in close juxtaposition.
Mobilization: The release of stem cells into the peripheral blood from the bone marrow compartment for the purpose of collecting these stem cells in anticipation of stem cell transplantation.
Mobitz type I: A type of second-degree AV nodal blockade.
Mobitz type II: A type of second-degree AV nodal blockade.
Moebius (also Möbius) syndrome: An extremely rare congenital neurologic disorder which is characterized by facial paralysis and the inability to move the eyes from side to side.
Monocytes: A variety of white blood cells.
Monoparesis: Slight or incomplete paralysis affecting a single extremity or part of one.
Monosodium urate: A crystallized form of uric acid that can deposit in joints leading to an inflammatory reaction and the symptoms of gout.
Mood lability: Unstable or changeable moods.
Morphology: The science of structure and form of cells without regard to function.
Motor tics: Involuntary brief spasmodic muscular movement or contraction, usually of the face or extremities.
Mu receptors: One of the three major classes of endogenous opioid receptors in the body. Mu receptors appear to be responsible for the majority of both the analgesic and rewarding properties of opioids.
Mucositis: Inflammation of mucous membranes, typically within the oral and esophageal mucosa. Usually associated with certain chemotherapy agents and radiation therapy involving mucosal areas.
Mucous colitis: A condition of the mucous membrane of the colon characterized by pain, constipation or diarrhea (sometimes alternating), and passage of mucus or mucous shreds.
Multiparity: Condition of having given birth to multiple children.
Mydriasis: Pronounced or abnormal dilation of the pupils.
Myelin: A protein and phospholipid sheath that surrounds the axons of certain neurons. Myelinated nerves conduct impulses more rapidly than nonmyelinated nerves.
Myeloablative preparative regimen: Radiation and/or chemotherapy that destroys bone marrow activity in preparation for a stem cell transplant. Patients will not likely recover bone marrow function without an infusion of “rescue” autologous or allogeneic stem cells. Myelodysplastic syndrome: A disease in which bone marrow does not function properly.
Myeloproliferative disorder: A group of diseases of bone marrow in which excess cells, usually lymphocytes, are produced.
Myelosuppression: Reduction in white blood cells, red blood cells, and platelets.
Myocarditis: Inflammation of the muscular wall of the heart.
Myoclonus: A sudden, involuntary jerking of a muscle or group of muscles.
Myoglobinuria: The presence of myoglobin in urine.
Myonecrosis: Necrotic damage to muscle tissue.
Myopathy: Any disease of the muscle causing weakness, pain, and tenderness.
Myringotomy: A surgical incision in the tympanic membrane to relieve pressure and drain fluid from the middle ear.
Myxedema: Relatively hard edema associated with hypothyroidism.
Nasal scotoma: An area of blindness in the nasal portion of peripheral vision.
Nascent: Immature.
Nasolacrimal occlusion: The closing of the tear duct to decrease systemic absorption of a drug.
Nausea: The subjective feeling of a need to vomit.
Necrotizing enterocolitis: Medical condition primarily seen in premature infants, where portions of the bowel undergo necrosis.
Nelson’s syndrome: A condition characterized by the aggressive growth of a pituitary tumor and hyperpigmentation of the skin.
Neoadjuvant therapy: Chemotherapy or radiation therapy given prior to primary surgical treatment. In cancer, it is often used to downstage the tumor to a resectable stage.
Neovascular maculopathy: Proliferation of blood vessels in the macula.
Neovascularization: New blood vessel formation (vascularization) especially in abnormal quantity (some conditions of the retina) or in abnormal tissue (tumor).
Nephrolithiasis: A condition marked by the presence of renal calculi (stones) in the kidney or urinary system.
Nephron: The working unit of the kidney that filters blood to remove fluid, toxins, and drugs. Each kidney contains approximately 1 million nephrons.
Nephrostomy: Insertion of a catheter through the skin into the renal pelvis to bypass ureteral obstruction and facilitate urine drainage.
Neuralgia: Pain which extends along the course of one or more nerves.
Neuritic (senile) plaque: An abnormal cluster of dead and dying nerve cells, other brain cells, and protein. One of the structural abnormalities found in the brains of patients with Alzheimer’s disease.
Neuritis: Inflammation of a nerve.
Neurofibrillary tangle: An accumulation of twisted protein fragments inside nerve cells; one of the structural abnormalities found in the brains of patients with Alzheimer’s disease.
Neuroimaging: Radiologic studies of the brain, usually referring to computerized tomography (CT) or magnetic resonance imaging (MRI).
Neurologic focality: Symptomatic sensory or motor deficits that point to specific lesions or dysfunction in the brain.
Neuropathic pain: Pain resulting from a lesion or dysfunction of the nervous system.
Neuropathy: An abnormal and usually degenerative state of the nervous system or nerves.
Neurotransmitters: Chemicals in the brain that allow the passage of a message between neurons or nerve cells.
Neutralizing antibodies: Antibodies that develop in response to a therapeutic agent that decrease the efficacy of the agent.
Nf-κB: Nuclear factor kappa B regulates cytokine production.
Nidus: A central point or focus consisting of a fibrin matrix (in the case of infective endocarditis), where bacteria are able to accumulate and multiply, allowing for formation of an infected vegetation.
Nitric oxide: An endogenous vasodilator.
Nociception: The perception of pain.
Nociceptors: Receptors for pain caused by injury from physical stimuli (mechanical, electrical, or thermal) or chemical stimuli (toxins); located in the skin, muscles, or in the walls of the viscera.
Nocturia: Micturition at night. Usually characterized by excessive urination at night.
Nocturnal polysomnography: Visual and electrophysiologic assessment of human sleep minimally composed of electroencephalogram, electrooculogram, and electromyogram that allows determination of sleep stage, breathing events, and muscle movements.
Nodules: When seen in rheumatoid arthritis, nodules are subcutaneous knobs over bony prominences or extensor surfaces.
Nonbacterial thrombotic endocarditis (NBTE): Endocarditis caused by noninfectious vegetations.
Nonmyeloablative preparative regimen: Radiation and/or chemotherapy that does not completely eradicate host bone marrow activity. Host bone marrow activity is suppressed but may recover after approximately 4 weeks even in the absence of “rescue” allogeneic stem cells.
Nonnucleoside reverse transcriptase inhibitor (NNRTI): A noncompetitive inhibitor of the viral reverse transcriptase enzyme by binding to the active site of the enzyme itself, rather than by terminating the enzymatic product. NNRTIs are only active against HIV-1.
Nonpolyposis: Absence of polyps.
Nonprotein kilocalorie-to-nitrogen ratio: Numerical value derived from dividing kilocalories from carbohydrate plus fat by the number of grams of nitrogen in the diet.
Non-REM sleep: A state of usually dreamless sleep that occurs regularly during a normal period of sleep with intervening periods of REM sleep and that consists of four distinct substages and low levels of autonomic physiological activity.
Non-ST-segment elevation: A type of myocardial infarction that is limited to the subendocardial myocardium and is smaller and less extensive than an ST-segment MI. Usually there is no pathologic Q wave on the ECG.
Normal flora: Normal colonizing bacteria of a human host.
Normochromic: Being normal in color; especially referring to red blood cells.
Normocytic: Normal size especially referring to red blood cells.
Nosocomial: An infection acquired within the health care system, e.g., hospital. Generally, symptoms of infection must occur after at least 48 hours of care to be considered nosocomial.
Nuchal rigidity: Neck stiffness.
Nuclear medicine scan: Method of body imaging that uses a radioactive tracer material (e.g., technetium and gallium) to produce body images. For example, bone scans detect uptake and cellular activity in areas of inflammation.
Nucleoside reverse transcriptase inhibitor (NRTI)/nucleotide reverse transcriptase inhibitor (NtRI): A modified version of a naturally occurring nucleoside or nucleotide that prevents HIV replication by interfering with the function of the viral reverse transcriptase enzyme. The nucleoside/nucleotide analog causes early termination of the proviral DNA chain. For activity, an NRTI requires three phosphorylation steps once inside the cell, whereas an NtRIs has a phosphate group attached and needs only two phosphorylation steps inside the cell for activity.
Nucleus accumbens: One of three nuclei that comprise the striatum (part of the basal ganglia). It receives dopaminergic input from the ventral tegmental area and is part of the limbic loop that plays a part in the motivational regulation of behavior and emotions.
Nulliparity: Not having given birth to a child.
Nystagmus: Rapid, involuntary movement of the eyes.
Obliterative bronchiolitis: Inflammation of the bronchioles (the small elements of the tracheobronchial tree) characterized by obliteration and/or permanent narrowing of the airways.
Off-label use: Use of a medication outside the scope of its approved, labeled use.
Offloading: Modalities, such as orthotics, that help off-weight/load an area of pressure, giving tissues time to heal without repetitive stress, which delays wound healing.
Oiling out: Continued coalescence of lipid emulsion particles, resulting in irreversible separation of the emulsion (or “breaking” of the emulsion).
Olfactory tubercle: Both the olfactory tubercle and the amygdala receive direct input from the olfactory bulb, and together they appear to help regulate the emotional, endocrine, and visceral consequences of odors.
Oligoanovulation: The condition of having few to no ovulatory menstrual cycles.
Oligoclonal bands: Small discrete bands in the γ-globulin region of fluid electrophoresis.
Oligohydramnios: Decreased amniotic fluid.
Oligomenorrhea: Abnormally light or infrequent menstruation.
Oliguria: Reduced urine output. Usually defined as less than 400 mL in 24 hours or less than 0.5 mL/kg/h.
Omentumectomy: Excision of the double fold of peritoneum attached to the stomach and connecting it with abdominal viscera (omentum).
Oncogene: Genes that cause transformation of normal cells into cancer cells by promoting uncontrolled cell growth and multiplication leading to tumor formation.
Oophorectomy: Surgery to remove the ovaries.
Open comedo: A plugged follicle of sebum, keratinocytes, and bacteria that protrudes from the surface of the skin and appears black or brown in color. Also referred to as a “blackhead.”
Opsonization: The process by which an antigen is altered so as to become more readily and more efficiently engulfed by phagocytes.
Optic neuritis: Usually monocular central visual acuity loss and ocular/periorbital pain caused by demyelination of the optic nerve.
Orbital/supraorbital: Pertaining to the eye socket and the area directly above it.
Orchiectomy: The surgical removal of the testicles.
Organification: Binding of iodine to tyrosine residues of thyroglobulin.
Orthopnea: Difficulty in breathing that occurs when lying down and is relieved upon changing to an upright position.
Orthostasis: Characterized by a drop in blood pressure when standing up from sitting or lying down, often causing lightheadedness and dizziness.
Orthotopic transplant: Placing a transplanted organ into the normal anatomic location.
Osmolality: A measure of the number of osmotically active particles per unit solution, independent of the weight or nature of the particle.
Osmolar gap: The difference between the measured serum osmolality and the calculated serum osmolality.
Osmophobia: A fear of strong odors and unpleasant smells; also called olfactophobia.
Osteoblasts: Cells involved in bone formation; “builders of bone.”
Osteoclasts: Cells involved in bone resorption; “creators of cavities.”
Osteomalacia: Softening of the bones.
Osteonecrosis: Death of bone tissue.
Osteopenia: Low bone density, which can lead to osteoporosis.
Osteophytes: Bony outgrowths (bone spurs) into the joint space.
Osteoporosis: Disease of the bones characterized by a loss of bone tissue, resulting in brittle, weak bones that are susceptible to fracture (porous bones).
Ostomy: Surgical operation where part of the abdominal wall is opened and part of the intestine is connected to the opening for intestinal draining, e.g., colostomy, ileostomy.
Otitis media with effusion: Fluid in the middle ear space with no signs or symptoms of an acute infection.
Ovulation: Periodic ripening and rupture of mature follicle and the discharge of ovum from the cortex of the ovary.
Oxygen desaturation: A decrease in the oxygen saturation of the blood. Oxygen saturation is described as the oxygen content of blood divided by oxygen capacity and expressed in volume percent.
Pacemaker: A mass of fibers that possess actual or potential automaticity, which initiates and determines the rate of spontaneous depolarizations.
Palliative care: According to the World Health Organization, the active, total care of patients whose disease is not responsive to curative treatment.
Palmar-plantar erythrodysesthesia (PPE): Syndrome characterized by numbness, tingling or burning sensations with edema, and redness of the hands and feet often resulting in cracked skin and blisters with marked peeling of skin.
Pancolitis: Inflammation that involves the majority of the colon in patients with inflammatory bowel disease.
Pancreatitis: Inflammation of the pancreas.
Panhypopituitarism: A clinical disorder characterized by complete deficiency in pituitary hormone production.
Pannus: Inflamed synovial tissue that invades and destroys articular structures.
Papilledema: Edema of the optic disc typically associated with increased intracranial pressure. Also called a choked disc.
Paracentral scotoma: Blind spots near the center of the visual field.
Parasomnia: Undesirable physical or behavioral phenomena (e.g., sleep walking, bruxism, enuresis, sleep talking, and REM behavior disorder) that occur predominantly during sleep.
Parenchyma: Specific cells or tissues of an organ.
Parenteral nutrition: Delivery of nutrients via the intravenous route.
Paresthesia: An abnormal touch sensation, such as burning or prickling, often in the absence of external stimulus.
Parieto-occipital: Located at the top and back of the head.
Paroxysmal: Intermittent occurrence, initiating suddenly and spontaneously, lasting minutes to hours, and terminating suddenly and spontaneously.
Pars reticulate: Dopaminergic cell bodies located in the substantia nigra that project to the thalamus and cortex. Considered one of the basal ganglia pathways; involved not only with movement but also with emotions, motivations, and cognition that drive movement.
Peak expiratory flow: The maximum flow rate of air leaving the lungs upon forced exhalation.
Pelvic inflammatory disease: Inflammation of the endometrium, uterine tubes, and pelvic peritoneum; often due to a sexually transmitted infection.
Percutaneous coronary intervention (PCI): A minimally invasive procedure whereby access to the coronary arteries is obtained through the femoral artery up the aorta to the coronary os. Contrast media is used to visualize the coronary artery stenosis using a coronary angiogram. A guidewire is used to cross the stenosis and a small balloon is inflated and/or stent is deployed to break up atherosclerotic plaque and restore coronary artery blood flow. The stent is left in place to prevent acute closure and restenosis of the coronary artery. Newer stents are coated with antiproliferative drugs, such as paclitaxel and sirolimus, which further reduce the risk of restenosis of the coronary artery.
Percutaneous endoscopic gastrostomy: Gastric feeding tube placed via endoscopic technique.
Percutaneous endoscopic jejunostomy: Jejunal feeding tube placed via endoscopic technique.
Perihilar: The area surrounding the depression in the medial surface of a lung that forms the opening through which the bronchus, blood vessels, and nerves pass.
Perimenopause: Also known as the climacteric, is the period of time prior to menopause when hormonal and biological changes and physical symptoms begin to occur and usually lasts for 1 year after the last menstrual period. The perimenopausal period may last for an average of 3 to 5 years.
Perimetry: Measurement of the field of vision.
Peripheral artery disease: Atherosclerosis of the peripheral arteries.
Peripheral resistance: The sum of resistance to blood flow offered by systemic blood vessels.
Peritonitis: An acute inflammatory reaction of the peritoneal lining to microorganisms or chemical irritation.
PET scan: A scan that produces images of the body after the injection of a radiolabeled form of glucose. A PET scan is often used to detect cancer or follow response to treatment since tumors use more sugar than normal cells.
Petechiae: Tiny localized hemorrhages from the small blood vessels just beneath the surface of the skin
Phagocytic cell: A cell that absorbs waste material, harmful microorganisms, or other foreign bodies in the bloodstream and tissues.
Phagocytosis: The process of engulfing and ingesting an antigen by phagocytes.
Pharmacodynamics: Describing the actions of a drug on the body or a part of the body, e.g., a receptor or organ.
Pharmacogenomic: The influence of genetic variation on drug response in patients, used to correlate gene expression with a drug’s efficacy or toxicity.
Pharmacokinetics: Refers to a mathematical method of describing a patient’s drug exposure in vivo in terms of absorption, distribution, metabolism, and elimination.
Pharyngitis: Inflammation and/or infection of the pharynx that causes throat pain.
Phenotype: The visible properties of an organism that are produced by the interaction of the genotype and the environment.
Pheochromocytoma: A tumor arising from chromaffin cells, most commonly found in the adrenal medulla. The tumor causes the adrenal medulla to hypersecrete epinephrine and norepinephrine resulting in hypertension and other signs and symptoms of excessive sympathetic nervous system activity. The tumor is usually benign but may occasionally be cancerous.
Phlebitis: Inflammation of a blood vessel, e.g., vein.
Phonophobia: A fear of sounds, loud noises, and even one’s own voice.
Photochemotherapy: The use of phototherapy together with topical or systemic drugs in the treatment of psoriasis.
Photodynamic therapy: Cancer treatment that uses interaction between laser light and a substance that makes the cells more sensitive to light. When light is applied to cells that have been treated with this substance, a chemical reaction occurs and destroys cancer cells.
Photophobia: An abnormal sensitivity to or intolerance of light.
Phototherapy: The use of ultraviolet light applied to the skin, e.g., in treating psoriasis or neonatal hyperbilirubinemia.
Physical dependence: A state of adaptation that is manifested by a drug-class specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist.
Piloerection: Erection of hairs, due to stimulation or contraction of the arrector pili muscles, also described as “gooseflesh.”
Pilosebaceous unit: A hair follicle and the surrounding sebaceous glands.
Plasma cell: Antibody producing cells.
Plasmapheresis: The process of separating blood cells from plasma. This process is used to remove the monoclonal antibodies from the blood.
Pleocytosis: A transient increase in the number of leukocytes in a body fluid.
Pleuritis: Inflammation of the lining around the lungs.
Pneumatic otoscopy: A diagnostic technique involving visualization of the tympanic membrane for transparency, position, and color, and its response to positive and negative air pressure to assess mobility.
Pneumothorax: The presence of air in the pleural cavity, often causing part of the lung to collapse.
Polycythemia: An abnormal increase in the number of erythrocytes in the blood.
Polydipsia: Excessive thirst.
Polymorphic metabolism: Genetically determined rates of metabolism (fast versus slow) by selected isozymes of cytochrome P450 drug-metabolizing enzymes.
Polymorphisms: Interindividual variations in the genetic code at the level of one nucleotide.
Polymorphonuclear leukocyte: A subgroup of white blood cells, filled with granules of toxic chemicals that enable them to digest microorganisms by phagocytosis.
Polyphagia: Eating excessively large amounts of food at a meal.
Polypharmacy: Taking multiple medications concurrently.
Polyp: A growth from a mucous membrane commonly found in organs such as the colon, rectum, and the nose. Usually not malignant, these can develop into cancer and require removal once found.
Polyuria: Excessive excretion of urine resulting in profuse micturition.
Portal hypertension: Increased blood pressure within the portal vein that supplies the liver.
Postpyloric feeding: Delivery of nutrients via a tube placed with its tip past the pyloric sphincter separating the stomach from the duodenum.
Prader-Willi syndrome: A genetic disorder characterized by short stature, mental retardation, low muscle tone, abnormally small hands and feet, hypogonadism, and excessive eating leading to extreme obesity.
Prediabetes: An asymptomatic but abnormal state that precedes the development of clinically evident diabetes.
Preload: The stretched condition of the heart muscle at the end of diastole just before contraction. Volume in the left ventricle at the end of diastole estimated by the pulmonary artery occlusion pressure (also known as the pulmonary artery wedge pressure or pulmonary capillary wedge pressure).
Preparative regimen (conditioning regimen): Radiation and/or chemotherapy given to stem cell transplant patients in order to kill malignant cells, create space in the bone marrow compartment, and suppress the immune system of the host in order to prevent graft rejection.
Priapism: A prolonged, painful erection lasting more than 4 hours. Considered a medical emergency.
Primary amenorrhea: Absence of menses by age 16 in the presence of normal secondary sexual development or absence of menses by age 14 in the absence of normal secondary sexual development.
Primary prevention: The removal or reduction of risk factors before the development of disease.
Prinzmetal angina: Vasospasm or contraction of the coronary arteries in the absence of significant atherosclerosis. Also referred to as variant angina.
Probiotics: Dietary supplements containing potentially beneficial bacteria that promote health by stimulating optimal mucosal immune responses.
Proctitis: Inflammation confined to the rectum in patients with inflammatory bowel disease.
Prodrome: Early symptom(s) indicating the onset of an attack or a disease.
Progenitor: A primitive cell.
Prolapse: Protrusion of an organ or part of an organ through an opening, e.g., uterine prolapse occurs when the uterus is displaced downward such that the cervix is within the vaginal opening (first degree), the cervix is outside the opening (second degree), or the entire uterus is outside the opening (third degree).
Proptosis: Forward displacement of the eyeball.
Prostaglandin: Any of a large group of biologically active, carbon-20, unsaturated fatty acids that are produced by the metabolism of arachidonic acid through the cyclooxygenase pathway.
Prostate specific antigen: This secretion of prostatic epithelial cells is used as a tumor marker for prostate cancer. It is not specific for prostate cancer. Thus, serum prostate-specific antigen concentrations may be increased in the face of any inflammatory or infectious disorder of the prostate, benign prostatic hyperplasia, or because of instrumentation of the prostate.
Prostatectomy: Surgical removal of the prostate, which can be performed transurethrally, suprapubically, or retropubically. There are two main types: transurethral prostatectomy (TURP) and radical prostatectomy. TURP removes part of the tissue surrounding the urethra, which may be blocking the flow of urine. Radical prostatectomy removes all of the prostate and the seminal vesicles.
Prostatic hyperplasia: Enlargement of the prostate.
Prosthetic-valve endocarditis (PVE): Endocarditis that occurs in patients with bioprosthetic or synthetic implanted heart valves.
Protease: Any one of various enzymes, including proteinases and peptidases, that catalyze the hydrolytic breakdown of proteins.
Protease inhibitor (PI): A drug that acts by inhibiting the viral protease enzyme, which prevents long strands of protein from being cleaved into the smaller proteins the virus requires for assembly.
Protectant: An agent that forms an occlusive barrier between the skin and surrounding moisture.
Protected specimen brush: Used in bronchoscopy, a brush in the lumen of a tube inside the bronchoscope. The brush is extended into the lung to obtain a sample, then retracted back into the tube for removal from the lung.
Proteinase: Any of numerous enzymes that catalyze the breakdown of proteins. Also called protease.
Proteinuria: The presence of measurable amounts of protein (greater than 150 mg/day) in the urine, which is often indicative of glomerular or tubular damage in the kidney.
Proteoglycan: Any one of a class of glycoproteins of high molecular weight that are found in the extracellular matrix of connective tissue. They are made up mostly of carbohydrate consisting of various polysaccharide side chains linked to a protein and resemble polysaccharides rather than proteins with regard to their properties.
Proteolysis: The hydrolysis of proteins, usually by enzyme action, into simpler substances.
Proteosome: An enzyme complex that degrades intracellular proteins.
Prothrombin: A clotting factor that is converted to thrombin. Also known as Factor II.
Prothrombin time: A measure of coagulation representing the amount of time required to form a blood clot after the addition of thromboplastin to the blood sample. Also known as Quick test.
Prothrombotic state: A state of high coagulation of the blood.
Pruritis: Localized or generalized itching due to irritation of sensory nerve endings.
Pseudoaddiction: A term used to describe patient behaviors (e.g., “drug-seeking,” “clock watching,” or illicit drug use) that may occur when pain is undertreated. Pseudoaddiction can be distinguished from true addiction in that the behaviors resolve when pain is effectively treated.
Pseudohyphae: Elongated forms created by replicating yeast that form buds but do not detach from one another.
Pseudophakia: Refers to presence of a lens after cataract extraction.
Pseudopolyps: An area of hypertrophied gastrointestinal mucosa that resembles a polyp and contains nonmalignant cells.
Pseudoseizure: Convulsions or seizure-like activity that results from causes other than abnormal electrical activity in the brain.
Psychodynamic: The explanation or interpretation of behavior or mood in terms of mental or emotional forces or processes.
Psychomotor retardation: A slowness of thought and physical movement that is primarily due to the psychological state.
Psychosocial: The interface between psychological and social functioning.
Pulmonary artery catheter: An invasive device used to measure hemodynamic parameters directly, including cardiac output and pulmonary artery occlusion pressure. Calculated parameters include stroke volume and systemic vascular resistance.
Pulmonary artery occlusion pressure: A hemodynamic measurement obtained via a catheter placed into the pulmonary artery used to evaluate patient volume status within the circulation.
Pulmonary embolism: A disorder of thrombus formation causing obstruction of a pulmonary artery or one of its branches and resulting in pulmonary infarction.
Pulsus paradoxus: A large fall in systolic blood pressure and pulse volume during inspiration or an abnormal variation in pulse volume during respiration in which the pulse becomes weaker with inspiration and stronger with expiration.
Purkinje fibers: Specialized myocardial fibers that conduct impulses from the AV node to the ventricles.
Purpura: A small hemorrhage of the skin, mucous membrane, or serosal surface.
Purulent: Containing, consisting of, or being pus.
Pyelonephritis: Inflammation of a kidney.
Pyloroplasty: A surgical procedure for enlarging the opening of the stomach to the duodenum.
Pyuria: Presence of pus in urine when voided.
Quality indicators: A list of indicators used by long-term care facility administrators and government overseers to identify potential problems in patient care.
Quality of Life: According the National Center for Chronic Disease Prevention and Health Promotion, the perceived physical and mental health over time.
Radiofrequency catheter ablation: Procedure during which radiofrequency energy is delivered through a catheter positioned at the atrioventricular node for the purpose of destroying one pathway of a reentrant circuit.
Raphe nuclei: Bed of serotonin containing neurons that extend to the hypothalamus, septum, hippocampus, and cingulated gyrus.
Recombinant activated factor VII: A clotting factor manufactured via recombinant technology used off-label (non-FDA approved) to foster clotting in hemorrhagic shock patients with massive hemorrhage refractory to conventional therapies such as fresh frozen plasma.
Rectal prolapse: Sinking of the rectum through the anal sphincter so that it is visible externally.
Recurrence: A relapse that occurs after a clear-cut recovery.
5α-Reductase: Intracellular enzyme in some target cells which activates testosterone to dihydrotestosterone. In these androgen-dependent target cells, dihydrotestosterone is more potent than testosterone.
Reentry: Circular movement of electrical impulses, a mechanism of many arrhythmias.
Refractory periods: The period of time after an impulse is initiated and conducted during which cells cannot be depolarized again.
Regurgitation: A passive process without involvement of the abdominal wall and the diaphragm wherein gastric or esophageal contents move into the mouth.
Relapse: The return of symptoms, satisfying the full syndrome criteria, after a patient has responded, but prior to recovery.
REM sleep: A state of sleep that recurs cyclically several times during a normal period of sleep and that is characterized by increased neuronal activity of the forebrain and midbrain, by depressed muscle tone, and by dreaming, rapid eye movements, and vascular congestion of the sex organs.
Remission: Relief of symptoms and return to full functioning in all areas of life.
Renin-angiotensin-aldosterone system: The hormonal system controlled mainly by the kidneys and adrenal glands that regulates blood pressure, blood volume, and electrolyte balance.
Replication capacity: This term is often used interchangeably with the term “viral fitness” and refers to how quickly an HIV reproduces or replicates. The slower HIV replicates, the less likely a patient is to have disease progression. A replication capacity may be reported on a resistance test. It is reported as a percentage of the median replication rate for drug-sensitive (wild-type) HIV strains.
Resorption: The process of bone breakdown by osteoclasts.
Respiratory acidosis: Acidosis that is caused by an accumulation of carbon dioxide.
Respiratory alkalosis: Alkalosis that is caused by a loss of carbon dioxide.
Respiratory disturbance index: A summary measure that quantifies the number of apneas, hypopneas, and respiratory effort-related arousals per hour of sleep.
Response: Refers to a predefined reduction of symptoms from baseline that generally results in significant functional improvement.
Response inhibition: Ability to stay on task.
Restenosis: Renarrowing of the coronary artery after a percutaneous intervention to improve coronary blood flow.
Retching: A process that follows nausea and consists of diaphragm, abdominal wall, and chest wall contractions and spasmodic breathing against a closed glottis.
Reticulocytes: Immature blood cells that mature into erythrocytes.
Reticuloendothelial system: Phagocytic cells excluding granulocytes; widely distributed throughout the body.
Retinopathy: The leading cause of blindness in people aged 20 to 74; occurs when the microvasculature nerve layer that provides blood and nutrients to the retina are damaged.
Retrograde ejaculation: Disorder in which semen flows in a backward fashion up the urethra and into the bladder during climax. The patient will complain of dry sex or no ejaculation during sexual intercourse, which may be worrisome to the patient.
Retroperitoneal fibrosis: An accumulation of fibrotic tissues located behind the organs contained in the abdominal sac.
Reye’s syndrome: A sudden, sometimes fatal, syndrome characterized by encephalopathy and liver degeneration, which occurs in children after viral infection and is also associated with aspirin use.
Rhabdomyolysis: A rapid lysis or destruction of skeletal muscles that can be associated with renal failure and death.
Rheumatic fever: An acute inflammatory disease involving the joints, heart, skin, brain, and other tissues caused by an immune response to streptococcal infection in genetically susceptible people, particularly in children.
Rheumatoid factors: Antibodies reactive with the Fc region of IgG.
Rhinorrhea: Nasal secretions; a runny nose.
Rhinosinusitis: Inflammation of the mucous membranes in the nose and sinuses.
Rhonchi: Abnormal, rumbling sounds heard on auscultation of an obstructed airway. They are more prominent during expiration and may clear somewhat on coughing.
Rouleaux formation: The stacking of red blood cells on a peripheral smear when diluted.
Rubefacient: A substance that produces redness of the skin.
Rule of six: A previously used weight-based guideline for calculating intravenous continuous infusions by multiplying body weight (kg) by six and adding this amount of drug to 100 mL of fluid, resulting in a concentration and infusion rate of 1 mcg/kg/min and 1 mL/h.
Salicylism: A toxic syndrome caused by excessive doses of acetylsalicylic acid (aspirin), salicylic acid, or any other salicylate product. Signs and symptoms may include severe headache, nausea, vomiting, tinnitus (ringing in the ears), confusion, increased pulse, and increased respiratory rate.
Scarlatiniform rash: Bright, scarlet-colored skin eruption that occurs in patches over the entire body with eventual peeling as a result of streptococcal infection.
Scleral icterus: Jaundice of the outer layer of the eyeball.
Scleritis: Inflammation of the outer layer of the eyeball.
Scoliosis: A congenital lateral curvature of the spine.
Scotoma: Referring to a partial loss of vision.
Secondary amenorrhea: Absence of menses for three cycles or 6 months in a previously menstruating woman.
Secondary hyperparathyroidism (sHPT): Increased secretion of parathyroid hormone from the parathyroid glands caused by hyperphosphatemia, hypocalcemia, and vitamin D deficiency that result from decreased kidney function. Secondary hyperparathyroidism can lead to bone disease (bone and mineral metabolism disorders).
Secondary prevention: Early detection of the premalignant condition or cancer, leading to earlier intervention.
Secondary transmission: Transferring a disease from the primary source to another person.
Seizure: A sudden attack due to involuntary electrical activity in the brain. It is caused by an uncontrolled burst of electrical activity in the brain that can result in a wide variety of clinical manifestation such as: muscle jerks or twitches, staring, tongue biting, loss of consciousness, and total body shaking.
Semiology: The clinical appearance or symptoms of a seizure.
Sentinel lymph node: The first lymph node to receive lymph draining from a tumor.
Sepsis: A syndrome characterized by a systemic inflammatory response (abnormal increases in body temperature, heart rate, respiratory rate, and/or white blood cell concentration) caused by infection.
Sera: Pertaining to human serum.
Serosa: An enclosing serous membrane of the pericardium, pleura, and peritoneum.
Serum ferritin: Quantifies the iron-binding capacity of transferring.
Serum sickness: A group of symptoms caused by a delayed immune response to certain medications. Arthralgias, fever, malaise, and urticaria may develop usually 7 to 14 days after exposure to the causative antigen.
Shear stress: Risk factor for pressure ulcers that is generated when the head of a patient’s bed is elevated and can cause deeper blood vessels to crimp, leading to ischemia.
Sialorrhea: Drooling.
Sick sinus syndrome: Idiopathic sinus node dysfunction leading to symptomatic sinus bradycardia.
Sickle cell anemia: Genetic disorder in which the red blood cells become crescent shaped.
Sickle cell syndrome: Describes a group of autosomal recessive genetic disorders that are characterized by the presence of at least one sickle hemoglobin gene.
Sickle hemoglobin: A defective form of hemoglobin produced as a result of a single substitution of the amino acid valine for glutamic acid at position 6 of the β-polypeptide chain.
Sigmoidoscopy: A visual inspection of the sigmoid colon and rectum with a flexible tube called a sigmoidoscope.
Simple disorder: The presence of a single acid–base disorder, with or without compensation.
Sjogren’s syndrome: An autoimmune disorder that causes inflammation of the salivary glands; decreasing the production of saliva, which is a buffer against esophageal erosions.
Sleep apnea: The temporary stopping of breathing during sleep; can be caused by narrowing of the airways resulting from swelling of soft tissue.
Sleep latency: The amount of time it takes to fall asleep.
Sliding scale insulin: An increase or decrease in the number of units of insulin administered to correct a blood glucose level at a particular point in time that does not prevent the problem from occurring and does not take into account differing total daily insulin requirements of patients.
Slit lamp biomicroscope: An instrument that allows for the microscopic examination of the cornea, anterior chamber lens, and posterior chamber.
Somatic hypermutation: The occurrence of multiple point mutations.
Somatotrope: Growth hormone producing cells in the anterior pituitary.
Somnolence: Prolonged drowsiness or sleepiness.
Source control: Removal of the primary cause of an infection such as contaminated prosthetic materials (e.g., catheters), necrotic tissue, or drainage of an abscess. Antimicrobials are unlikely to be effective if the process or source that led to the infection is not controlled.
Spastic colon: A synonym for irritable bowel syndrome.
Spasticity: A motor disorder characterized by an increase in muscle tone with exaggerated tendon jerks, resulting from hyperexcitability of the stretch reflex.
Spectrum of activity: A qualitative term that describes the number of different bacterial species that are susceptible to an antimicrobial regimen. Generally, broad-spectrum activity refers to regimens that possess activity against many bacterial species, whereas narrow-spectrum therapy refers to activity against a few bacterial species.
Sphincter of Oddi: Structure through which the common bile duct empties bile and pancreatic secretions into the duodenum.
Spirometry: Measurement by means of a spirometer of the air entering and leaving the lungs.
Splenomegaly: An enlarged spleen secondary to leukemic infiltration.
Spontaneous bacterial peritonitis: Bacterial infection of the peritoneal fluid without abdominal source.
Sprain: An overstretching of supporting ligaments that results in a partial or complete tear of the ligament.
Status epilepticus: Any seizure lasting more than 30 minutes, with or without a loss of consciousness; or having recurrent seizures without regaining consciousness between seizure episodes.
Steatohepatitis: A severe form of liver disease caused by fat deposition in the liver, characterized by hepatic inflammation that may rapidly progress to liver fibrosis and cirrhosis.
Steatorrhea: Excessive loss of fat in stool.
Steatosis: Excessive fat accumulation.
Stenosis: Blockage of an artery.
Stenting: Placement of a stent to allow blood flow through an artery.
Stereotactic radiosurgery: Radiation technique that uses a large number of narrow, precisely aimed, highly focused beams of ionizing radiation. The beams are aimed from many directions circling the head and meet at a specific point.
Stereotyped 'font-size:13.5pt; font-family:"Times New Roman",serif;color:black'> Behavior that is associated with repetitive postures or movements without meaning.
Stevens-Johnson syndrome: A severe expression of erythema multiforme (also known as erythema multiforme major). It typically involves the skin and the mucous membranes with the potential for severe morbidity and even death.
Stimulant: Any amphetamine or amphetamine-like substance (methylphenidate) that causes an increase in dopaminergic and norepinephrine activity in the brain resulting in lessening of hyperactivity, impulsiveness and/or inattentiveness.
Stomatitis: Inflammation of mucous membranes in the mouth.
Strain: Damage to the muscle fibers or muscle sheath without tearing of the ligament.
Stretta procedure: Application of radiofrequency to increase lower esophageal sphincter tone.
Striae: Linear, atrophic, pinkish or purplish, scar-like lesions that later become white (striae albicantes, lineae albicantes), which may occur on the abdomen, breasts, buttocks, and thighs. They are due to weakening of the elastic tissues; commonly called stretch marks.
Stricture: Abnormal narrowing of a tubular structure in the body. An area of narrowing or constriction in the gastrointestinal tract due to buildup of fibrotic tissue, often a result of longstanding inflammation.
Stroke volume: The amount of blood ejected from the heart during systole.
ST-segment elevation: A type of myocardial infarction that typically results in an injury that transects the thickness of the myocardial wall. Following an ST-elevation MI, pathologic Q waves are frequently seen on the ECG, indicating transmural myocardial infarction.
Subchondral: Situated beneath and supporting cartilage.
Substantia nigra: The area in the brainstem with highly pigmented cells that make dopamine.
Surgical margins: An area of tissue surrounding a tumor when it is removed by surgery.
Surgical site infection: Infections occurring at or near the surgical incision within 30 days of the operation; up to 1 year if a prosthesis is implanted.
Suspending agent: An additive used in the compounding of oral liquid medications to suspend drug particles throughout a liquid and enables resuspension of particles by agitation (shaking well).
Synechia: Adhesions or the abnormal attachment of the iris to another structure. Peripheral anterior synechia refers to occurrence of synechia with the trabecular meshwork.
Synovitis: Inflammation of the synovial membrane, often in combination with pain and swelling of the affected joint.
Synovium: Membrane lining the internal surfaces of the joint.
Systolic dysfunction: An abnormal contraction of the ventricles during systole.
Tachycardia: Abnormally fast heart rate.
Tachyphylaxis: Rapid decreasing response to a drug or other physiologically active agent after a few doses.
Tachypnea: Abnormally fast respiratory rate.
Tangentiality: Abandoning one’s ideational objective in pursuit of thoughts peripheral to the original goal. Used to describe a thought and speech pattern wherein the individual never gets to the point or answers the question.
Tardive dyskinesia: A chronic disorder of the nervous system characterized by involuntary jerky or writhing movements of the face, tongue, jaws, trunk, and limbs, usually developing as a late side effect of prolonged treatment with antipsychotic drugs.
Telangiectasia: Permanent dilation of preexisting small blood vessels (capillaries, arterioles, and venules), usually in the skin or mucous membranes which presents as a coarse or fine red line.
Tendonitis: Inflammation of the tendon.
Tenesmus: Refers to straining, especially painful, or ineffectual straining with a bowel movement or straining on defecation owing to spasms of an inflamed rectal sphincter as occurs in shigellosis.
Tenosynovitis: Inflammation of the tendon sheath.
Teratogen: An exogenous agent or substance that can modify normal embryonic or fetal development. The manifestation of teratogenicity can include structural anomalies, functional deficit, cancer, growth retardation, and death (spontaneous abortion, stillbirth).
Teratogenic potential: The ability of an agent to cause harm or malformations to a fetus or embryo. Medications are assigned pregnancy categories based on their teratogenic potential.
Teratogenicity: The property of causing malformations in the developing fetus.
Terminal secretions: The noise produced by the oscillatory movements of secretions in the upper airways in association with the inspiratory and expiratory phases of respiration. Also known as “death rattle.”
Tetany: Hyperexcitability of nerves and muscles characterized by muscular twitching and cramps, laryngospasm with inspiratory stridor, and hyperreflexia.
Third spacing: Fluid accumulation in the interstitial space disproportionate to the intracellular and extracellular fluid spaces.
Thoracentesis: Removal of fluid that is present in the pleural space. Common procedure to determine cause of the fluid accumulation.
Thrombin: The enzyme formed from prothrombin, which converts fibrinogen to fibrin. It is the principal driving force in the clotting cascade.
Thrombocytopenia: Decrease in platelet concentration in the blood.
Thrombocytosis: Increased number of platelets in the blood.
Thrombogenesis: The process of forming a blood clot.
Thrombolysis: The process of enzymatically dissolving or breaking apart a blood clot.
Thrombolytic: An enzyme that dissolves or breaks apart blood clots.
Thrombophlebitis: Inflammation of a blood vessel (e.g., a vein) associated with the stimulations of clotting and formation of a thrombus (or blood clot).
Thromboplastin: A substance that triggers the coagulation cascade. Tissue factor is a naturally occurring thromboplastin and is used in the prothrombin time test.
Thrombosis: The process of forming a thrombus.
Thrombotic thrombocytopenic purpura: Condition characterized by formation of small clots within the circulation resulting in the consumption of platelets and a low platelet count.
Thrombus: Blood clot attached to the vessel wall and consisting of platelets, fibrin and clotting factors. A thrombus may partially or completely occlude the lumen of a blood vessel compromising blood flow and oxygen delivery to distal tissue.
Thymoma: A tumor derived from the epithelial or lymphoid elements of the thymus.
Thyroglobulin: A thyroid hormone-containing protein, usually stored in the colloid within the thyroid follicles.
Thyroid peroxidase: Enzyme that catalyzes the organification and coupling steps of thyroid hormone synthesis.
Thyroiditis: Inflammation of the thyroid gland.
Thyrotoxicosis: State caused by excess amount of thyroid hormone.
Tocolytic: Medication used to suppress premature labor.
Tolerance: A state of adaptation in which exposure to a drug induces changes that result in a diminution of one or more of the drug’s effects over time.
Tonometry: A method by which the cornea is indented or flattened by an instrument. The pressure required to achieve corneal indentation or flattening is a measure of intraocular pressure.
Tophi: Chalky deposits of sodium urate occurring in gout; tophi form most often around joints in cartilage, bone, bursae, and subcutaneous tissue and in the external ear, producing a chronic, foreign-body inflammatory response. If untreated, tophi can lead to joint deformity or destruction.
Topoisomerase: Enzyme that temporarily alters supercoiled DNA by cutting the DNA causing the DNA to relax the supercoil during DNA replication. Topoisomerase inhibitors prevent the DNA from sealing the cut which causes DNA strand breakage.
Torsade de pointes: Very rapid ventricular tachycardia characterized by a gradually changing QRS complex in the ECG; may change into ventricular fibrillation.
Toxic epidermal necrolysis: A life-threatening skin disorder characterized by blistering and peeling of the top layer of skin.
Toxoid: A modified bacterial exotoxin that has lost toxicity.
Tracheal aspirate: Suctioning of secretions from the trachea.
Transaminases: Hepatocellular enzymes that are released into the bloodstream after hepatic damage.
Transesophageal echocardiogram: Procedure used to generate an image of the heart via sound waves, via a probe introduced into the esophagus (rather than the traditional transthoracic view) in order to obtain a better image of the left atrium.
Transferrin saturation: Indicates the amount of transferrin that is bound with iron.
Transient ischemic attack: Focal neurologic deficit lasting less than 24 hours in which symptoms resolve completely.
Translocation: Movement of bacteria and endotoxin from the intestinal lumen through the gut mucosa and into the lymphatic and systemic circulation.
Transmural: Across the wall of an organ or structure. In Crohn’s disease, inflammation may extend through all four layers of the intestinal wall.
Transsphenoidal pituitary microsurgery: Surgery through the nasal cavity to access the pituitary gland through the sphenoid bone.
Transvenous pacing: Insertion of a pacemaker into the heart via venous access for the purpose of pacing.
Traveler’s diarrhea: An acute infectious diarrhea that afflicts travelers during or immediately upon return from visits to other countries. The presence of at least three loose stools within 24 hours that are associated with nausea, vomiting, abdominal pain, fecal urgency, or dysentery.
Tremulousness: Exhibiting trembling or shaking.
Trigeminal neuralgia: A disorder of the fifth cranial (trigeminal) nerve characterized by excruciating paroxysms of pain in the face.
Trigeminovascular: The complex of vascular supply to and from the trigeminal nerve. The trigeminal nerve is the fifth cranial nerve responsible for pain perception in the head and face.
Trophic: Stimulatory effect.
Troponins T or I: Proteins found predominately in cardiac and not skeletal muscle which regulates calcium-mediated interaction of actin and myosin. Troponin I and T are released into the blood from the myocytes at the time of myocardial cell necrosis secondary to infarction. These biochemical markers become elevated and are used in the diagnosis of myocardial infarction. Troponin I and T are more sensitive and specific for infarction than creatine kinase, which is found in both skeletal and myocardial cells. The exact value of troponin I or T, which is diagnostic of infarction, differs based upon assay.
Tubal ligation: Surgical process of tying up the fallopian tubes to prevent passage of ova from the ovaries to the uterus.
Tuberoeruptive xanthomas: Small yellow–red raised papules usually presenting on the elbows, knees, back, and buttocks.
Tubulointerstitial: Involving the tubules or interstitial tissue of the kidneys.
Tumor lysis syndrome: A syndrome resulting from cytotoxic therapy, occurring generally in aggressive, rapidly proliferating lymphoproliferative disorders. It is characterized by combinations of hyperuricemia, lactic acidosis, hyperkalemia, hyperphosphatemia, and hypocalcemia.
Tumor suppressor gene: A gene that suppresses growth of cancer cells.
T2-weighted magnetic resonance imaging: A setting of the magnetic resonance imaging machine that shows water as a bright signal.
Tympanocentesis: Puncture of the tympanic membrane with a needle to aspirate middle ear fluid.
Tympanostomy tube: Small plastic or metal tube inserted into the eardrum to keep the middle ear aerated and improve hearing in patients with chronic middle ear effusion.
Uhthoff’s phenomenon: Acute worsening of multiple sclerosis symptoms on exposure to heat because high body temperatures may exceed the capacitance of the demyelinated nerve and conduction may fail.
Ulceration: A suppurative or nonhealing lesion on a surface such as skin, cornea, or mucous membrane.
Ultrafiltration: The movement of plasma water across a semipermeable membrane.
Ultrasound: Noninvasive imaging of organ or tissue to detect fluid, masses, or cyst.
Uncomplicated disorder: The presence of a single acid–base disorder, with or without compensation. See also Simple disorder.
Unilateral: Pertaining to one side.
Uremia: A condition that results from accumulation of metabolic waste products and endogenous toxins in the body resulting from impaired kidney function. Symptoms of uremia include nausea, vomiting, weakness, loss of appetite and mental confusion.
Uric acid: A by-product of purine metabolism in mammals, including humans. A high serum uric acid concentration is a major risk factor for gout.
Uricosuric: Pertaining to, characterized by, or promoting renal secretion of uric acid.
Urosepsis: Sepsis resulting from a urinary source.
Urticaria: Itchy, raised, swollen areas on the skin. Also known as hives.
Uveitis: An inflammation of the uvea, including the iris, ciliary body or choroid.
Vagal maneuvers: Stimulate the activity of the parasympathetic nervous system, which inhibits AV nodal conduction. Examples of vagal maneuvers include cough, carotid sinus massage, and Valsalva.
Vagotomy: A surgical procedure that blocks vagal (cholinergic) stimulation to the stomach.
Valsalva maneuver: Vagal maneuver; patient bears down against a closed glottis, as if they were having a bowel movement.
Variceal bleeding: Gastric, esophageal, or rectal bleeding from collateral vessels (varices).
Vasculitis: Inflammation of the walls of blood vessels.
Vasopressors: Medications that cause constriction of blood vessels, increase in vascular resistance, and increase in blood pressure.
Vasospasm: Narrowing (constriction) of a blood vessel causing a reduction in blood flow.
Ventilation/perfusion ratio (Va/Q): A comparison of the proportion of lung tissue being ventilated by inhaled air to the rate of oxygenation of pulmonary blood.
Ventral tegmental area: Part of the basal ganglia, containing dopamine neurons that project to the striatum, specifically the nucleus accumbens. This is part of the reward pathway in the brain.
Ventricular depolarization: Change in the membrane potential of a ventricular myocyte, resulting in loss of polarization. Under normal conditions, depolarization of ventricular myocytes is followed by ventricular contraction.
Vertigo: Sensation of spinning or feeling out of balance.
Vesicants: Chemotherapy drugs that cause significant tissue damage if extravasation occurs.
Virilization: Production or acquisition of virilism or the possession of masculine characteristics.
Volvulus: Twisting of the intestine causing obstruction and possible necrosis.
Vomiting: A reflexive rapid and forceful oral expulsion of upper gastrointestinal contents due to powerful and sustained contractions in the abdominal and thoracic musculature.
Waist circumference: A practical tool to measure the abdominal fat in patients with a BMI of less than 35.
Wernicke’s syndrome: A syndrome that can be associated with chronic alcohol use, characterized by loss of memory, disorientation, and confabulation.
Western blot (WB): “Gold standard” for HIV diagnostic testing. Disrupted virus is purified, gel electrophoresed to separate by molecular weight to form bands corresponding to the nine HIV antigens, and blotted onto a membrane support. HIV serum antibodies from the patient are allowed to bind to proteins in the membrane support. If HIV antibodies from the patient are bound, the bands will change color. The test is considered reactive if two of the three major bands (p24, gp41, and/or gp120/160) change color. The test is nonreactive if no viral bands are visible.
Wheeze: A high pitched whistling sound caused by air moving through narrowed airways. Wheezes are usually heard at the end of expiration but may be heard during inspiration and expiration in acute severe asthma.
White coat hypertension: A persistently elevated average office blood pressure of greater than 140/90 mm Hg and an average awake ambulatory reading of less than 135/85 mm Hg.
Wilson’s disease: A disorder of copper metabolism, characterized by cirrhosis of the liver and neurologic manifestations.
Xanthoma: Firm, raised nodules composed of lipid-containing histiocytes.
Xerostomia: Dryness of the mouth resulting from diminished or arrested salivary secretion.
ZAP-70 expression: An intracellular tyrosine kinase found in CLL B-cells.