Webster's New World Medical Dictionary

aldosteronism
See 
Conn syndrome.
alexia
Loss of the ability to read or understand
the written word, due either to brain damage that
disconnects these functions or to temporary dys-
function caused by abnormal electrical or chemical
activity in the brain.
alienist
French term for a psychologist, a psychi-
atrist, or another practitioner who cares for the
mentally ill.
alimentary
Concerning food, nourishment, and
the organs of digestion. From the Latin 
alimentum,
meaning nourishment.
alkaline phosphatase
An enzyme that liberates
phosphate under alkaline conditions and is made in
liver, bone, and other tissues. Alkaline phosphatase
can be measured in a routine blood test.
Abnormally high serum levels of alkaline phos-
phatase may indicate bone disease, liver disease, or
bile duct obstruction.
alkalosis
Relatively too much base in the blood
and body, an abnormal condition resulting from the
accumulation of base or the depletion of acid. The
pH of an alkalotic body measures above normal.
The opposite of alkalosis is acidosis.
alkaptonuria
A genetic metabolic disorder due
to deficiency of the enzyme homogentisic acid
(HGA) dioxygenase. Deficiency of this enzyme leads
to the three cardinal features of alkaptonuria (the
presence of homogentisic acid in the urine),
ochronosis (bluish-black pigmentation in connec-
tive tissue), and arthritis. Urine that turns dark is a
characteristic feature.
allele
An alternative form of a gene.
allergen
A substance that can cause an allergic
reaction. Common allergens include ragweed
pollen, animal dander, and mold.
allergic conjunctivitis
Inflammation of the
whites of the eyes (conjunctivae), with itching, red-
ness, and tearing, due to allergy.