Health and Medicine

In human beings, the extent of an individual’s continuing physical, emotional, mental, and social ability to cope with his environment. This definition, just one of many that are...

• abortion

  the expulsion of a fetus from the uterus before it has reached the stage of viability (in human beings, usually about the 20th week of gestation). An abortion may occur spontaneously, in which case it is also called a miscarriage, or it may be brought...

• achondroplasia

  genetic disorder characterized by an abnormality in the conversion of cartilage into bone. As a consequence, bones that depend on cartilage models for development, particularly long bones such as the femur and humerus, cannot grow. Achondroplasia is...

• acupressure

  alternative-medicine practice in which pressure is applied to points on the body aligned along 12 main meridians (pathways), usually for a short time, to improve the flow of qi (life force). Though often referred to by its Japanese name, shiatsu, it...

• acupuncture

  ancient Chinese medical technique for relieving pain, curing disease, and improving general health. It was devised before 2500 bce in China and by the late 20th century was used in many other areas of the world. Acupuncture consists of the insertion...

• Adams, Robert

  clinician noted for his contributions to the knowledge of heart disease and gout. In 1827 he described a condition characterized by a very slow pulse and by transient giddiness or convulsive seizures, now known as the Stokes-Adams disease or syndrome....

• Addison, Thomas

  English physician after whom Addison’s disease, a metabolic dysfunction caused by atrophy of the adrenal cortex, and Addison’s (pernicious) anemia were named. He was the first to correlate a set of disease symptoms with pathological changes in one of...

• adolescence

  transitional phase of growth and development between childhood and adulthood. The World Health Organization (WHO) defines an adolescent as any person between ages 10 and 19. This age range falls within WHO’s definition of young people, which refers to...

• adulthood

  the period in the human lifespan in which full physical and intellectual maturity have been attained. Adulthood is commonly thought of as beginning at age 20 or 21 years. Middle age, commencing at about 40 years, is followed by old age at about 60 years....

• aerospace medicine

  specialized branch of medical science concerned with those medical problems encountered in human flight in the atmosphere (aviation medicine) and beyond the atmosphere (space medicine). The ultimate aim of this specialty is to promote the safety and...

• affective disorder

  mental disorder characterized by dramatic changes or extremes of mood. Affective disorders may include manic (elevated, expansive, or irritable mood with hyperactivity, pressured speech, and inflated self-esteem) or depressive (dejected mood with disinterest...

• Agramonte y Simoni, Aristides

  physician, pathologist, and bacteriologist, a member of the Reed Yellow Fever Board of the U.S. Army that discovered (1901) the role of the mosquito in the transmission of yellow fever. Agramonte was the son of a prominent physician who had been killed...

• Agricola, Georgius

  German scholar and scientist known as “the father of mineralogy.” While a highly educated classicist and humanist, well regarded by scholars of his own and later times, he was yet singularly independent of the theories of ancient authorities. He was...

• AIDS

  transmissible disease of the immune system caused by the human immunodeficiency virus (HIV). HIV is a lentivirus (literally meaning “slow virus”; a member of the retrovirus family) that slowly attacks and destroys the immune system, the body’s defense...

• albinism

  (from the Latin albus, meaning “white”), hereditary condition characterized by the absence of pigment in the eyes, skin, hair, scales, or feathers. Albino animals rarely survive in the wild because they lack the pigments that normally provide protective...

• Aldrovandi, Ulisse

  Renaissance naturalist and physician noted for his systematic and accurate observations of animals, plants, and minerals. After studying mathematics, Latin, law, and philosophy, Aldrovandi went to Padua in about 1545 to continue his studies. There he...

• Allbutt, Sir Thomas Clifford

  English physician, the inventor of the short clinical thermometer. His investigations also led to the improved treatment of arterial diseases. During a 28-year practice in Leeds, Allbutt made valuable clinical studies, primarily of arterial and nervous...

• allergy

  hypersensitivity reaction by the body to foreign substances (antigens) that in similar amounts and circumstances are harmless within the bodies of other people. Antigens that provoke an allergic reaction are called allergens. Typical allergens include...

• Alpini, Prospero

  physician and botanist who is credited with the introduction to Europe of coffee and bananas. While a medical adviser to Giorgio Emo, the Venetian consul in Cairo (1580–83), Alpini made an extensive study of Egyptian and Mediterranean flora. He is reputed...

• Alzheimer disease

  degenerative brain disorder that develops in mid-to-late adulthood. It results in a progressive and irreversible decline in memory and a deterioration of various other cognitive abilities. The disease is characterized by the destruction of nerve cells...

• amniocentesis

  the surgical insertion of a hollow needle through the abdominal wall and into the uterus of a pregnant female and the aspiration of fluid from the amniotic sac for analysis. Examination of the amniotic fluid itself as well as the fetal cells found in...