What Is Polycystic Ovary Syndrome?Polycystic ovary syndrome is a common health problem that can affect teenage girls and women. Although no one really knows what causes PCOS, it seems to be related to an imbalance in a girl's hormones.Both girls and guys produce sex hormones, but in different amounts. In girls, the ovaries produce the hormones estrogen and progesterone, and also androgens. These hormones regulate a girl's menstrual cycle and ovulation, when the egg is released. Even though androgens are sometimes referred to as “male hormones,” every female produces them.In girls with PCOS, the ovaries produce higher than normal amounts of androgens, and this can interfere with egg development and release. Sometimes instead of the eggs maturing, cysts, which are little sacs filled with liquid, develop. Instead of an egg being released during ovulation, like during a normal menstrual cycle, the cysts build up in the ovaries and may become enlarged. Because girls with PCOS are not ovulating or releasing an egg each month, it's common for them to have irregular or missed periods.Although PCOS (which used to be called Stein-Leventhal syndrome) was first recognized in the 1930s, doctors can't say for sure what causes it. Research has suggested that PCOS may be related to increased insulin production in the body. Women with PCOS may produce too much insulin, which signals their ovaries to release extra male hormones. PCOS seems to run in families, too, so if someone in your family has it, you might be more likely to develop it.If PCOS is not treated properly, it can put a girl at risk for lots of problems. Girls with PCOS are more likely to have infertility, excessive hair growth, acne, obesity, diabetes, heart disease, high blood pressure, abnormal bleeding from the uterus, and cancer.The good news is that, although there's no cure for PCOS, it can be treated. The most important step is diagnosing the condition, because getting treatment for PCOS reduces a girl's chances of having serious side effects.