Polycystic ovarian syndrome (PCOS) is a hormonal disorder that affects a woman's menstrual cycle, fertility, hormones, heart, blood vessels, and appearance. PCOS is caused by a hormonal imbalance and insulin resistance. It is diagnosed based on symptoms, medical history, physical exam, blood tests, and ultrasound. Treatment focuses on symptoms, fertility goals, and prevention of diabetes and heart disease through lifestyle changes, medication, and sometimes surgery. Women with PCOS have higher risks of health problems like diabetes, heart disease, and mental health issues.