The exact cause of PCOS is not known. Factors that might play a role include:

• Excess insulin. Insulin is the hormone produced in the pancreas that allows cells to use sugar, your body’s primary energy supply. If your cells become resistant to the action of insulin, then your blood sugar levels can rise and your body might produce more insulin. Excess insulin might increase androgen production, causing difficulty with ovulation.
• Low-grade inflammation. This term is used to describe white blood cells’ production of substances to fight infection. Research has shown that women with PCOS have a type of low-grade inflammation that stimulates polycystic ovaries to produce androgens, which can lead to heart and blood vessel problems.
• Heredity. Research suggests that certain genes might be linked to PCOS.
• Excess androgen. The ovaries produce abnormally high levels of androgen, resulting in hirsutism and acne.