Endometriosis occurs when cells from the lining of your womb (uterus) grow in other areas of your body. This can cause pain, heavy bleeding, bleeding between periods, and problems getting pregnant (infertility).


Every month, a woman's ovaries produce hormones that tell the cells lining the uterus to swell and get thicker. Your uterus sheds these cells along with blood and tissue through your vagina when you have your period.

Endometriosis occurs when these cells grow outside the uterus in other parts of your body. This tissue may attach on your:

It can grow in other areas of the body, too.

These growths stay in your body, and like the cells in the lining of your uterus, these growths react to the hormones from your ovaries. They grow and bleed when you get your period. Over time, the growths may add more tissue and blood. The buildup of blood and tissue in your body leads to pain and other symptoms.

No one knows what causes endometriosis. One idea is that when you get your period, the cells may travel backwards through the fallopian tubes into the pelvis. Once there, the cells attach and grow. However, this backward period flow occurs in many women. Researchers think that the immune system plays a role in causing endometriosis in women with the condition.

Endometriosis is common. It occurs in about 10% of women of reproductive age. Sometimes, it may run in families. Endometriosis probably starts when a woman begins having periods. However, it usually is not diagnosed until ages 25 to 35.

You are more likely to develop endometriosis if you:


Pain is the main symptom of endometriosis. You may have:

Other symptoms of endometriosis include:

You may not have any symptoms. Some women with a lot of tissue in their pelvis have no pain at all, while some women with milder disease have severe pain.

Exams and Tests

Your health care provider will perform a physical exam, including a pelvic exam. You may have one of these tests to help diagnose the disease:


Learning how to manage your symptoms can make it easier to live with endometriosis.

What type of treatment you have depends on:

There is currently no cure for endometriosis. There are different treatment options.


If you have mild symptoms, you may be able to manage cramping and pain with:


These medicines can stop endometriosis from getting worse. They may be given as pills, nasal spray, or shots. Only women who are not trying get pregnant should have this therapy. Hormone therapy will prevent you from getting pregnant. Once you stop therapy, you can get pregnant again.

Birth control pills -- With this therapy, you take the hormone pills (not the inactive or placebo pills) for 6 to 9 months continuously. Taking these pills relieves most symptoms. However, it does not treat any damage that has already occurred.

Progesterone pills or injections -- This treatment helps shrink growths. Side effects may include weight gain and depression.

Gonadotropin-agonist medicines -- These medicines stop your ovaries from producing the hormone estrogen. This causes a menopause-like state. Side effects include hot flashes, vaginal dryness, and mood changes. Treatment is often limited to 6 months because it can weaken your bones. Your provider may give you small doses of hormone to relieve symptoms during this treatment. This is known as 'add-back' therapy. It may also help protect against bone loss, while not triggering growth of the endometriosis.


Your provider may recommend surgery if you have severe pain that does not get better with other treatments.

Outlook (Prognosis)

There is no cure for endometriosis. Hormone therapy can help relieve symptoms, but symptoms often return when therapy is stopped. Surgical treatment may help relieve symptoms for years. However, not all women with endometriosis are helped by these treatments.

Once you enter menopause, endometriosis is unlikely to cause problems. 

Possible Complications

Endometriosis can lead to problems getting pregnant. However, most women with mild symptoms can still get pregnant. Laparoscopy to remove growths and scar tissue may help improve your chances of becoming pregnant. If it does not, you may want to consider fertility treatments.

Other complications of endometriosis include:

In rare cases, endometriosis tissue may block the intestines or urinary tract.

Very rarely, cancer may develop in the areas of tissue growth after menopause.

When to Contact a Medical Professional

Call your provider if:

You may want to get screened for endometriosis if:


Birth control pills may help to prevent or slow down the development of the endometriosis. Birth control pills used as treatment for endometriosis work best when taken continuously and not stopped to allow a menstrual period. They may be used for young women in late adolescence or early 20s with painful periods that may be due to endometriosis.

Review Date: 2/13/2018
Reviewed By: John D. Jacobson, MD, Professor of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda Center for Fertility, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 04/08/2019.

This information should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. © 1997- 2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.