Polycystic ovary syndrome (PCOS) is a hormonal disorder that affects women of reproductive age. The exact cause of PCOS is not known, but it is thought to be related to abnormal hormone levels. Factors that might play a role in the development of PCOS include insulin resistance, which can lead to high levels of insulin and androgens. Insulin is a hormone produced by the pancreas that allows cells to use sugar, your bodys primary energy supply. If cells become resistant to the action of insulin, then blood sugar levels can go up, causing your body to make more insulin to try to bring down the blood sugar level. This can cause your ovaries to produce more androgens, which can interfere with ovulation and cause the symptoms of PCOS. Hormonal imbalances, such as raised levels of testosterone, luteinising hormone (LH), and prolactin, and low levels of sex hormone-binding globulin (SHBG), may also contribute to the development of PCOS. PCOS may also run in families, suggesting a genetic link.