CausesBy Mayo Clinic staff
Doctors don't know the cause of polycystic ovary syndrome, but these factors likely play a role:
- Excess insulin. Insulin is the hormone produced in the pancreas that allows cells to use sugar (glucose) — your body's primary energy supply. If you have insulin resistance, your ability to use insulin effectively is impaired, and your pancreas has to secrete more insulin to make glucose available to cells. The excess insulin might boost androgen production by your ovaries.
- Low-grade inflammation. Your body's white blood cells produce substances to fight infection in a response called inflammation. Eating certain foods can trigger an inflammatory response in some predisposed people. When this happens, white blood cells produce substances that can lead to insulin resistance and cholesterol accumulation in blood vessels (atherosclerosis). Atherosclerosis causes cardiovascular disease. Research has shown that women with PCOS have low-grade inflammation.
- Heredity. If your mother or sister has PCOS, you might have a greater chance of having it, too. Researchers also are looking into the possibility that mutated genes are linked to PCOS.
- Abnormal fetal development. Some research shows that excessive exposure to male hormones (androgens) in fetal life may permanently prevent normal genes from working the way they're supposed to — a process known as gene expression. This may promote a male pattern of abdominal fat distribution, which increases the risk of insulin resistance and low-grade inflammation. Researchers continue to investigate to what extent these factors might contribute to PCOS.
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