It is most common in women under 30 years old. The ovaries produce the female hormones estrogen and progesterone. Before menopause, they also produce eggs.
Ovarian cysts are fluid-filled sacs that result from ovulation cycles.
Many ovarian cysts go away without treatment. The most common cysts are just enlargements of normal egg follicles. This disorder has also been called Stein-Leventhal syndrome. Polycystic ovary syndrome is caused by an abnormal production of two hormones by the pituitary gland in the brain. Imbalance of these hormones prevents the ovaries from releasing an egg each month.