An ovarian cyst is a sac filled with fluid that forms on or inside an ovary.
This article is about cysts that form during your monthly menstrual cycle, called functional cysts. Functional cysts are not the same as cysts caused by cancer or other diseases.
Each month during your menstrual cycle, a follicle grows on your ovary. The follicle is where an egg is developing. Most months, an egg is released from this follicle, called ovulation. If the follicle fails to break open and release an egg, the fluid stays in the follicle and forms a cyst. This is called a follicular cyst.
Another type of cyst occurs after an egg has been released from a follicle. This is called a corpus luteum cyst. This type of cyst often contains a small amount of blood.
Ovarian cysts are more common in the childbearing years between puberty and menopause. The condition is less common after menopause.
Taking fertility drugs can cause a condition in which multiple large cysts are formed on the ovaries. This is called ovarian hyperstimulation syndrome. The cysts most often go away after a woman's period, or after a pregnancy.
Functional ovarian cysts are not the same as ovarian tumors, or cysts due to hormone-related conditions such as polycystic ovary syndrome.
Ovarian cysts often cause no symptoms.
An ovarian cyst is more likely to cause pain if it:
Symptoms of ovarian cysts can also include:
Changes in menstrual periods are not common with follicular cysts, and are more common with corpus luteum cysts. Spotting or bleeding may occur with some cysts.
Your doctor or nurse may discover a cyst during a pelvic exam, or when you have an ultrasound test for another reason.
Ultrasound may be done to diagnose a cyst. Your doctor or nurse may want to check you again in 6 - 8 weeks to make sure it is gone.
Other imaging tests that may be done when needed include:
The following blood tests may be done:
Functional ovarian cysts often do not need treatment. They often go away on their own within 8 - 12 weeks.
If you have frequent cysts, your doctor or nurse may prescribe birth control pills (oral contraceptives). These medicines may reduce the risk of new ovarian cysts. Birth control pills do not decrease the size of current cysts.
Surgery to remove the cyst or ovary may be needed to make sure that it is not ovarian cancer. Surgery is more likely to be needed for:
Types of surgery for ovarian cysts include:
You may need other treatments if you have polycystic ovary syndrome or another disorder that can cause cysts.
Cysts in women who are still having periods are more likely to go away. A complex cyst in a woman who is past menopause has a higher risk of being cancer. Cancer is very unlikely with a simple cyst.
Complications have to do with the condition causing the cysts. Complications can occur with cysts that:
Call your health care provider if:
Also call your health care provider if you have had following on most days for at least 2 weeks:
If you are not trying to get pregnant and you often get functional cysts, you can prevent them by taking hormone drugs (such as birth control pills). These medicines prevent follicles from growing.
Reviewed By: Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, WA; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.