An ovarian cyst is a fluid-filled sac in the ovary. The most common type of ovarian cyst – a functional cyst – often disappears without treatment. It is believed that most women of reproductive age have functional cysts from time to time. These cysts usually disappear within one or two menstrual cycles and women are rarely even aware of them. Occasionally, this sort of cyst will persist or grow very large, causing symptoms.

The most common symptom of an ovarian cyst is pain in the lower abdomen. Ovarian cysts are almost never cancerous when they occur in women of reproductive age. However, your doctor should investigate any pelvic pain.

In addition to functional cysts, there are several less common types of ovarian cysts. For example, endometriosis can cause cysts on the ovary; and polycystic ovary syndrome is sometimes, though not always, characterized by multiple cysts in the ovaries.