What is PCOS? If you're wondering... Polycystic ovary syndrome is a condition in which there is an imbalance of a woman's female sex hormones. This hormone imbalance may cause changes in the menstrual cycle, skin changes, small cysts in the ovaries, trouble getting pregnant, and other problems. Causes, incidence, and risk factors Female sex hormones include estrogen and progesterone, as well as hormones called androgens. Androgens, often called "male hormones," are also present in women, but in different amounts. Hormones help regulate the normal development of eggs in the ovaries during each menstrual cycle. Polycystic ovary syndrome is related to an imbalance in these female sex hormones. Too much androgen hormone is made, along with changes in other hormone levels. It is not completely understood why or how the changes in the hormone levels occur. Follicles are sacs within the ovaries that contain eggs. Normally, one or more eggs are releas...