Polycystic ovarian syndrome (PCOS) is a common hormonal disorder in women that interferes with the growth and release of eggs from the ovaries (ovulation). It is the most common cause of infertility among women. PCOS occurs when a woman's body overproduces sex hormones, called androgens. The hormone imbalance prevents fluid-filled sacs in the ovaries from breaking open and releasing mature eggs. The fluid-filled sacs bunch together, causing many tiny cysts. Symptoms of PCOS include missed periods, abnormal facial and body hair growth, acne, and weight gain. PCOS may run in families. Follow the links below to find BootsWebMD's comprehensive coverage about PCOS, what the symptoms are, how to treat it, and much more.