Webster's New World Medical Dictionary

polycystic kidney disease, autosomal reces-
sive
An early-onset disorder that is characterized
by the presence of innumerable cysts in the kidneys
and enlarged kidneys that can usually be detected
via ultrasound before birth or in the neonatal
period. Some cases are diagnosed later in child-
hood. The gene for the disease is on chromosome
6. Also known as infantile polycystic kidney disease.
polycystic kidney disease, infantile
See 
poly-
cystic kidney disease, autosomal recessive.
polycystic ovarian disease
See 
polycystic
ovarian syndrome.
polycystic ovarian syndrome
A hormonal
problem, also known as polycystic ovarian disease,
that causes women to have symptoms that include
irregular or no menstruation, acne, obesity, and
excess hair growth. Abbreviated PCOS. Women with
PCOS do not ovulate (release an egg for fertilization)
every month. They are at an increased risk for high
blood pressure, diabetes, heart disease, and cancer
of the uterus (endometrial cancer). Much of this
risk can be reversed with exercise and weight loss.
Medication is generally prescribed to induce regular
menstruation, thereby reducing the cancer risk. For
acne and excess hair growth, the diuretic medication
spironolactone (brand name: Aldactazide) can help.
Clomiphene (brand name: Clomid) can be used to
induce ovulation if pregnancy is desired. Surgical
procedures involving the removal or destruction of a
piece of the ovary seem to help some women. The
cause of PCOS is unknown, but the ovaries of
affected women contain a number of small cysts.
Also known as Stein-Leventhal syndrome. 
polycythemia
Too many red blood cells. The
opposite of polycythemia is anemia. Polycythemia
exists when the hemoglobin, red blood cell (RBC)
count, and total RBC volume are all above normal.
Polycythemia can lead to heart failure, stroke, and
other medical problems when severe. Treatment
can involve bloodletting. See 
polycythemia vera.