Normally, endometrial tissue is found only inside the uterus. The uterus is the reproductive organ where a fetus develops. Hormones cause the tissue to form there, preparing the body for a fertilized egg. If you do not become pregnant, the tissue leaves the body during menstruation.
In endometriosis, endometrial-like tissue is found outside the uterus. For example, it may be found on organs in the abdomen or pelvis. In these places, the tissue still responds to hormones. It swells, breaks down, and bleeds. But it is unable to leave when you menstruate. Surrounding tissue becomes inflamed. There is often scarring.
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Possible causes include:
- Menstrual tissue backs up through the fallopian tubes and spills into the abdomen
- Immune system may allow the tissue to implant on other organ surfaces and develop into endometriosis
- Lymph system may carry endometrial cells from the uterus
- Certain cells left behind on abdominal organs during embryonic development can turn into endometrial tissue
Hormones and growth factors cause the disease to progress.
Risk Factors ^
Factors that may increase your risk of endometriosis include:
- Family history—a mother or sister with endometriosis
- Early onset of menstruation
- Not having children—Pregnancy slows or stops the disease from progressing. The condition usually resolves at menopause. The symptoms may return with hormone replacement therapy.
- Prolonged menstrual bleeding—more than 7-8 days
- Abnormal development of the uterus, with a blocked segment
Symptoms range from mild to severe. There may be many large growths with little pain. Or, there may be small areas with intense pain.
You will be asked about your symptoms and medical history. A pelvic exam will be done. These are best done early in the menstrual period. Diagnosis is usually confirmed with a laparoscopy. This test allows the doctor to see if there are patches of endometrial tissue and scar tissue.
The goals of treatment are to:
- Control pain
- Slow endometrial growth
- Restore or preserve fertility
Treatment options depend on:
- Severity of symptoms
- Size, number, and location of growths
- Degree of scarring
- Extent of the disease
- Age and whether a baby is wanted in the future
They following medications may be advised:
- Over-the-counter pain relievers to ease mild symptoms
- Nonsteroidal anti-inflammatory drugs to reduce inflammation and help with cramping—best when taken on a regular basis
- Prescription pain relievers—often needed
Hormones are an option for women who are not trying to become pregnant. Birth control pills and other injectable drugs interfere with estrogen production. These medications may decrease pain and shrink the size and number of endometrial growths. But, symptoms and endometrial growths tend to come back when the hormones are stopped. If birth control pills are prescribed to manage endometriosis, then they are often used continuously, so that menstruation does not occur. After surgery, birth control pills may reduce the chance of these growths returning.
If there are severe symptoms or a pregnancy is wanted in the future, then doctors can try to remove endometrial growths. This is often done with laparoscopic surgery. In severe, unmanageable cases it may be advised to also remove the uterus and ovaries. But this means that pregnancy cannot happen.
There are no current guidelines to prevent endometriosis.
The American College of Obstetricians and Gynecologists
The Society of Obstetricians and Gynaecologists of Canada
Women's Health Matters
American Academy of Family Physicians. Endometriosis: what you should know. Am Fam Physician. 2006;74(4):601-602.
Endometriosis. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T115220/Endometriosis. Updated May 25, 2017. Accessed September 11, 2017.
Endometriosis. The National Institute of Child Health and Human Development website. Available at: http://www.nichd.nih.gov/health/topics/endometri/Pages/default.aspx. Accessed September 11, 2017.
Practice bulletin no. 114: management of endometriosis. Obstet Gynecol. 2010;116(1):223-236. Reaffirmed 2016.
3/12/2010 DynaMed Plus Systematic Literature Surveillancehttp://www.dynamed.com/topics/dmp~AN~T115220/Endometriosis: Seracchioli R, Mabrouk M, Frascà C, et al. Long-term cyclic and continuous oral contraceptive therapy and endometrioma recurrence: a randomized controlled trial. Fertil Steril. 2010;93(1):52-56.
Last reviewed September 2017 by EBSCO Medical Review Board Beverly Siegal, MD, FACOG Last Updated: 9/23/2014