Polycystic ovary syndrome (say "pah-lee-SIS-tik OH-vuh-ree SIN-drohm") is a problem in which a woman's hormones are out of balance. It can cause problems with your periods and make it difficult to get pregnant. PCOS also may cause unwanted changes in the way you look. If it isn't treated, over time it can lead to serious health problems, such as diabetes and heart disease.
Most women with PCOS grow many small cysts camera.gif on their ovaries. That is why it is called polycystic ovary syndrome. The cysts are not harmful but lead to hormone imbalances.
Hormones are chemical messengers that trigger many different processes, including growth and energy production. Often, the job of one hormone is to signal the release of another hormone.
The cause of PCOS is not fully understood, but genetics may be a factor. PCOS seems to run in families, so your chance of having it is higher if other women in your family have it or have irregular periods or diabetes. PCOS can be passed down from either your mother's or father's side.