- A women's reproductive system has two ovaries, one on either side of the uterus. The ovaries, each about the size of an almond, produce eggs (called ova) as well as the female sex hormones estrogen and progesterone. Eggs are fertilized by sperm from the male to produce offspring.
- An ovarian cyst is a sac filled with fluid that forms on or inside an ovary. Any ovarian follicle that is larger than about two centimeters is termed an ovarian cyst. An ovarian cyst can be as small as a pea or larger than a cantaloupe.
- Ovarian cysts affect women of all ages. They occur most often, however, during a woman's childbearing years. Some ovarian cysts cause problems, such as bleeding and pain. Functional ovarian cysts usually don't need treatment and typically disappear on their own within 8-12 weeks. Surgery may be required to remove cysts larger than five centimeters in diameter.