Polycystic ovary syndrome (PCOS) is a group of health problems linked to a woman's out-of-balance hormones. Common symptoms of PCOS include irregular periods, infertility, repeat miscarriages, male-pattern hair loss, male-type facial and body hair, acne, and obesity. PCOS raises your risks for serious health problems, including high blood pressure (hypertension), heart disease, diabetes, and uterine (endometrial) cancer.

Reproductive problems

Hormone imbalances linked to PCOS cause several types of pregnancy problems and related problems, including:

• Infertility. This happens when the ovaries are not releasing an egg every month.
• Repeat miscarriages. The cause for this is not known. These miscarriages may be linked to high insulin levels, delayed ovulation, or other problems such as the quality of the egg or how the egg attaches to the uterus.
• Gestational diabetes during pregnancy. This risk is greater in women with PCOS than in women who ovulate regularly.
• Increased blood pressure during pregnancy or delivery, having a larger than normal or smaller than normal baby, or having a premature baby.
• Precancer of the uterine lining (endometrial hyperplasia). This can happen when you don't have regular menstrual cycles, which normally build up and "clear off" the uterine lining every month. You can take birth control pills or other hormone medicines to reduce the risk of endometrial hyperplasia.
• Uterine (endometrial) cancer. Risk during the reproductive years is 3 times greater in women with PCOS than in women who ovulate monthly.⁷

You may have more regular menstrual cycles as you near menopause. The reason for this is not known. But your history of PCOS may still increase your long-term risk of high blood pressure (hypertension), heart disease, diabetes, or endometrial cancer.

Problems with insulin and sugar metabolism

Insulin is a hormone that helps your body's cells get the sugar they need for energy. Sometimes these cells do not fully respond to the action of insulin. This is called insulin resistance. Insulin resistance can lead to an increase in blood sugar and diabetes.

Up to 40% of women with PCOS have insulin resistance, and up to 10% get type 2 diabetes by the time they reach age 40.³ Insulin levels also rise in people with insulin resistance. High insulin levels can increase the production of male hormones and make your PCOS worse.

Serious health problems linked to insulin resistance include:

• High blood pressure.
• High triglycerides.
• Low HDL ("good") cholesterol.
• High blood sugar.
• Excess body fat (particularly abdominal obesity).

Heart and blood circulation problems

It is possible that high insulin from PCOS makes heart and blood vessel problems worse.³ These problems include:

• Hardening of the arteries (atherosclerosis).
• Coronary artery disease and heart attack. Some studies have shown that heart attack risk may be increased by as much as 7 times in women with PCOS compared with women who don't have PCOS.⁸
• High blood pressure.
• High cholesterol.
• Stroke.

Breathing/sleep problems

Women with PCOS have a higher risk of breathing problems while sleeping (obstructive sleep apnea). This is linked to both obesity and insulin resistance.³