Harvard Medical School Glossary of Health Terms

GlossaryThe Harvard Medical School Glossary of Health Terms is a comprehensive glossary that defines more than 2,000 terms in clear, simple language. Entries cover a range of topics, from anatomy and physiology to diseases and words related to nutrition, fitness, and mental health. 

Glossary of Health Terms Sample Entries

alpha blockers: A group of drugs that lower blood pressure by blocking the effects of adrenaline or adrenaline-like substances on cells' alpha receptors. Also used to treat some prostate gland problems. Alpha blockers are also known as alpha-adrenergic antagonists, alpha-adrenergic blocking agents, and alpha-adrenergic blockers.

arteriosclerosis: A term encompassing a variety of conditions in which artery walls thicken and become less flexible. Sometimes called hardening of the arteries. Arteriosclerosis occurs when cholesterol-rich plaque forms on the inner lining of arteries (atherosclerosis), when artery walls become calcified, or when high blood pressure thickens the muscular wall of arteries.

body mass index (BMI): A measure of body fat estimated from a person’s height and weight. A healthy BMI is defined as 18.5 to 24.9. BMI = weight (in kilograms) divided by height (in meters) squared. Using English units, multiply weight in pounds by 703, then divide the result by height in inches, and divide that result by height in inches.

cartilage: Stiff connective tissue that provides support to other tissues and cushions joints.

diuretic: A drug that eases the heart's workload and decreases the buildup of fluid in the lungs and other parts of the body by promoting the excretion of water and salts. Diuretics (also called water pills) are used to treat high blood pressure, heart failure, and some congenital heart defects.

diverticulitis: The bulging out of small pouches or sacs of tissue from the colon wall.

durable power of attorney: A legal document in which an individual appoints another person to make medical, financial, or other decisions when the individual becomes unable to make those decisions.

endocarditis: An inflammation of the heart lining or valves, usually caused by bacterial infection.

exercise stress test: The use of a treadmill, stationary bicycle, or other exercise machine while hooked up to heart-monitoring equipment. The test is used to determine if the heart's blood supply is sufficient and if the rhythm remains normal when the heart is stressed.

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