alpha-fetoprotein A plasma protein normally produced by a fetus, principally in the fetus’s liver, the fetal gastrointestinal tract, and the yolk sac, a structure temporarily present during embryonic development. Abbreviated AFP. The level of AFP is typically high in the fetus’s blood. It goes down after birth. By 1 year of age, it is virtually…
Alport syndrome A hereditary condition characterized by kidney disease, deafness, and sometimes eye defects. Alport syndrome involves inflammation of the kidney (nephritis), often progressing to kidney failure, and sensory nerve hearing loss. Progression to kidney failure is gradual and usually occurs in males before 50 years of age.
ALS Amyotropic lateral sclerosis, Lou Gehrig’s disease.
ALT Alanine aminotransferase.
alternative medicine Healing arts not taught in traditional Western medical schools that promote options to conventional medicine that is taught in these schools. An example of an alternative therapy is using a special diet to treat cancer instead of undergoing surgery, radiation, or chemotherapy that has been recommended by a Western physician. Complementary medicine is…
altitude, acclimatization to See acclimatization to altitude.
altitude illness See altitude sickness.
altitude sickness Sickness caused by being at a high altitude, usually above 2,400 meters (approximately 8,000 feet). The cause of altitude sickness is a matter of oxygen physiology. At sea level the concentration of oxygen is about 21 percent, and the barometric pressure averages 760 mm Hg. As altitude increases, the concentration remains the same,…
alveolitis Inflammation of the alveoli, the air sacs in the lungs.
alveolus A tiny air sac in the lungs. Plural alveoli.
Alzheimer’s disease A progressive degenerative disease of the brain that leads to dementia. On a cellular level, Alzheimer’s disease is characterized by the finding of unusual helical protein filaments in nerve cells of the brain. These twisted filaments are called neurofibrillary tangles. In the brain, Alzheimer’s disease involves degeneration of the cortical regions, especially the…
AMA American Medical Association, a professional organization for physicians that sets widely accepted standards of practice and ethics and that publishes the weekly journal JAMA ( Journal of the American Medical Association).