The polycystic ovary syndrome (PCOS) is an extremely common disorder that o
ccurs in 4% to 7% of women of reproductive age. Although PCOS is known to b
e associated with reproductive morbidity and increased risk for endometrial
cancer, diagnosis is especially important because PCOS is now thought to i
ncrease metabolic and cardiovascular risks. These risks are strongly linked
to insulin resistance and are compounded by the common occurrence of obesi
ty, although insulin resistance and its associated risks are also present i
n nonobese women with PCOS. Women with PCOS are at increased risk for impai
red glucose tolerance, type 2 diabetes mellitus, and hypertension. Cardiova
scular disease is believed to be more prevalent in women with PCOS, and it
has been estimated that such women also have a significantly increased risk
for myocardial infarction. Many lipid abnormalities (most notably low high
-density lipoprotein cholesterol levels and elevated triglyceride levels) a
nd impaired fibrinolysis are seen in women with PCOS. Early diagnosis of th
e syndrome and close long-term follow-up and screening for diabetes and car
diovascular disease are warranted. An opportunity exists for preventive the
rapy, which should improve the reproductive, metabolic, and cardiovascular
risks.