Endometriosis(en-doh-mee-tree-OH-suhs) happens when the lining of the uterus (womb) grows outside of the uterus. It affects about 5 million American women.1 Endometriosis is especially common among women in their 30s and 40s. The most common symptom is pain. The pain happens most often during your period, but it can also happen at other times. Endometriosis may also make it harder to get pregnant. Several different treatment options can help manage the symptoms and improve your chances of getting pregnant.
Endometriosis, sometimes called "endo," is a common health problem in women. It gets its name from the word endometrium, (en-doh-MEE-tree-um) the tissue that normally lines the uterus or womb. Endometriosis happens when this tissue grows outside of your uterus and on other areas in your body where it doesn't belong.
Endometriosis growths are benign (not cancerous). But they can still cause problems.
Endometriosis happens when tissue that is normally on the inside of your uterus or womb grows outside of your uterus or womb where it doesn't belong. Endometriosis growths bleed in the same way the lining inside of your uterus does every month — during your menstrual period. This can cause swelling and pain because the tissue grows and bleeds in an area where it cannot easily get out of your body.
The growths may also continue to expand and cause problems, such as:
Blocking your fallopian tubes when growths cover or grow into your ovaries. Trapped blood in the ovaries can form cysts.
Forming scar tissue and adhesions (type of tissue that can bind your organs together). This scar tissue may cause pelvic pain and make it hard for you to get pregnant.
No one knows for sure what causes this disease. Researchers are studying possible causes:
Problems with menstrual period flow. Retrograde menstrual flow is the most likely cause of endometriosis. Some of the tissue shed during the period flows through the fallopian tube into other areas of the body, such as the pelvis.
Genetic factors. Because endometriosis runs in families, it may be inherited in the genes.
Immune system problems. A faulty immune system may fail to find and destroy endometrial tissue growing outside of the uterus. Immune system disorders and certain cancers are more common in women with endometriosis.
Hormones. The hormone estrogen appears to promote endometriosis. Research is looking at whether endometriosis is a problem with the body's hormone system.
Surgery. During a surgery to the abdominal area, such as a Cesarean (C-section) or hysterectomy, endometrial tissue could be picked up and moved by mistake. For instance, endometrial tissue has been found in abdominal scars.
You can't prevent endometriosis. But you can reduce your chances of developing it by lowering the levels of the hormone estrogen in your body. Estrogen helps to thicken the lining of your uterus during your menstrual cycle.
To keep lower estrogen levels in your body, you can:
Talk to your doctor about hormonal birth control methods, such as pills, patches or rings with lower doses of estrogen.
Exercise regularly (more than 4 hours a week).2 This will also help you keep a low percentage of body fat. Regular exercise and a lower amount of body fat help decrease the amount of estrogen circulating through the body.
Avoid large amounts of alcohol. Alcohol raises estrogen levels.3 No more than one drink per day is recommended for women who choose to drink alcohol.
Avoid large amount of drinks with caffeine. Studies show that drinking more than one caffeinated drink a day, especially sodas and green tea, can raise estrogen levels.4
If you have symptoms of endometriosis, talk with your doctor. The doctor will talk to you about your symptoms and do or prescribe one or more of the following to find out if you have endometriosis:
Pelvic exam. During a pelvic exam, your doctor will feel for large cysts or scars behind your uterus. Smaller areas of endometriosis are harder to feel.
Imaging test. Your doctor may do an ultrasound to check for ovarian cysts from endometriosis. The doctor or technician may insert a wand-shaped scanner into your vagina or move a scanner across your abdomen. Both kinds of ultrasound tests use sound waves to make pictures of your reproductive organs. Magnetic resonance imaging (MRI) is another common imaging test that can make a picture of the inside of your body.
Medicine. If your doctor does not find signs of an ovarian cyst during an ultrasound, he or she may prescribe medicine:
Hormonal birth control can help lessen pelvic pain during your period.
Gonadotropin(go-na-doh-TRO-pen)releasing hormone (GnRH) agonists block the menstrual cycle and lower the amount of estrogen your body makes. GnRH agonists also may help pelvic pain.
If your pain gets better with hormonal medicine, you probably have endometriosis. But, these medicines work only as long as you take them. Once you stop taking them, your pain may come back.
Laparoscopy(lap-ar-OS-ko-pee). Laparoscopy is a type of surgery that doctors can use to look inside your pelvic area to see endometriosis tissue. Surgery is the only way to be sure you have endometriosis. Sometimes doctors can diagnose endometriosis just by seeing the growths. Other times, they need to take a small sample of tissue and study it under a microscope to confirm this.
There is no cure for endometriosis, but treatments are available for the symptoms and problems it causes. Talk to your doctor about your treatment options.
If you are not trying to get pregnant, hormonal birth control is generally the first step in treatment. This may include:
Extended-cycle (you have only a few periods a year) or continuous cycle (you have no periods) birth control. These types of hormonal birth control are available in the pill or the shot and help stop bleeding and reduce or eliminate pain.
Intrauterine device (IUD) to help reduce pain and bleeding. The hormonal IUD protects against pregnancy for up to 7 years. But the hormonal IUD may not help your pain and bleeding due to endometriosis for that long.
Hormonal treatment works only as long as it is taken and is best for women who do not have severe pain or symptoms.
If you are trying to get pregnant, your doctor may prescribe a gonadotropin-releasing hormone (GnRH) agonist. This medicine stops the body from making the hormones responsible for ovulation, the menstrual cycle, and the growth of endometriosis. This treatment causes a temporary menopause, but it also helps control the growth of endometriosis. Once you stop taking the medicine, your menstrual cycle returns, but you may have a better chance of getting pregnant.
Surgery is usually chosen for severe symptoms, when hormones are not providing relief or if you are having fertility problems. During the operation, the surgeon can locate any areas of endometriosis and may remove the endometriosis patches. After surgery, hormone treatment is often restarted unless you are trying to get pregnant.
Other treatments you can try, alone or with any of the treatments listed above, include:
Pain medicine. For mild symptoms, your doctor may suggest taking over-the-counter medicines for pain. These include ibuprofen (Advil and Motrin) or naproxen (Aleve).
Complementary and alternative medicine (CAM) therapies. Some women report relief from pain with therapies such as acupuncture, chiropractic care, herbs like cinnamon twig or licorice root, or supplements, such as thiamine (vitamin B1), magnesium, or omega-3 fatty acids.5
For some women, the painful symptoms of endometriosis improve after menopause. As the body stops making the hormone estrogen, the growths shrink slowly. However, some women who take menopausal hormone therapy may still have symptoms of endometriosis.
If you are having symptoms of endometriosis after menopause, talk to your doctor about treatment options.
All material contained in this fact sheet is free of copyright restrictions, and may be copied, reproduced, or duplicated without permission of the Office on Women's Health in the Department of Health and Human Services. Citation of the source is appreciated.
This fact sheet was reviewed by:
Esther Eisenberg, M.D., M.P.H., Medical Officer, Project Scientist, Reproductive Medicine Network, Fertility and Infertility Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development
E. Britton Chahine, M.D., FACOG, Gynecologic Surgeon at The Center for Innovative GYN Care