Webster's New World Medical Dictionary

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 cel-
lular 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 frontal and temporal
lobes. There is currently no cure for Alzheimer’s
disease, but new medications and therapies appear
to slow its progress and improve the patient’s ability
to function.
AMA
American Medical Association, a profes-
sional 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)
.
amastia
A rare condition wherein the normal
growth of the breast or nipple does not occur.
Unilateral amastia (absence of one breast) is often
associated with absence of the pectoral muscles.
Bilateral amastia (absence of both breasts) is asso-
ciated with multiple birth defects involving other
parts of the body. See also 
amazia.
amaurosis fugax
A symptom that is often
described as a shade coming down over the eye.
Amaurosis fugax is a partial or complete loss of
sight that is temporary. Amaurosis fugax is usually
caused by arteriosclerosis in the blood vessels that
supply the brain. It can also occur with excessive
acceleration, as in flight, and with ophthalmic
migraine. See also 
arteriosclerosis.
amaurotic familial idiocy
An outdated term for
Tay-Sachs disease (TSD). See 
Tay-Sachs disease.
amazia
A condition wherein the breast tissue is
absent, but the nipple is present. Amazia is typically
a result of radiation or surgery.