What causes endometriosis?

The most widely accepted cause of endometriosis is retrograde menstruation. This occurs when tissue from the uterine lining (endometrial tissue) flows backward through your fallopian tubes while you're menstruating and implants in various sites, most commonly in the pelvis. The tissue gets trapped and can't leave the body.

However, no matter where it is in the body, endometrial tissue still responds to your hormones each month. This tissue can become inflamed, bleed and develop into scar tissue. When the tissue is attached to organs in the pelvic and abdominal cavities, it may cause severe pain, infertility and other problems.

Other theories suggest that alterations in the immune system response, hormonal imbalances or environmental causes may be related to the development of endometriosis. Experts also have found strong evidence suggesting a genetic link.

This content originally appeared on HealthyWomen.org.
The cause of endometriosis is unknown, according to Jessica Ritch, MD, Gynecologist at Aventura Hospital & Medical Center. Learn more about endometriosis in this video.
Monica M. Diaz, MD
OBGYN (Obstetrics & Gynecology)
The current theory to the cause of endometriosis is retrograde menstruation. In this video, Monica Diaz, MD, OB/GYN at Medical City Dallas Hospital describes how blood, glands and tissue may be pushed out and implanted during the menstruation cycle.
Edmond E. Pack, MD
OBGYN (Obstetrics & Gynecology)
Doctors are not sure what causes endometriosis, says Edmond Pack, MD, an OB/GYN at Southern Hills Hospital. In this video, he discusses a common theory of its cause, and outlines other problems created by endometriosis.
Sangeeta Senapati, MD
OBGYN (Obstetrics & Gynecology)
It is unclear what causes endometriosis. There are several theories as to what might contribute to its growth.
One theory is that there is some back flow of blood into the fallopian tubes during the menstrual period. This endometrial tissue/blood may then go into the abdominal cavity and implant into various location in the abdomen.
Another theory is that some of the endometrial cells from the inner lining of the uterus make their way into the blood or lymphatic streams. From they are taken to various parts of the body and deposited resulting in endometrial implants.
Yet another theory suggests that there might be genetic and immunologic factors that predispose women to develop this condition.
The cause is likely some combination of the above theories but further research needs to be done to determine this.
No one knows what causes endometriosis, but they have several theories as to its origination. Some believe endometriosis is caused by the backward flow of blood during menstruation, which spreads endometrial tissue to other parts of the body. Others believe that endometrial cells can be spread to different parts of the body through the blood or lymph systems. Some researchers speculate that some cells outside of the uterus have the potential to turn into endometrial cells. It may also be due to an immune disorder or family history. Whatever the root cause, it is known that the symptoms of endometriosis begin because of displaced endometrial tissue swelling and bleeding mostly during menstruation.

Continue Learning about Endometriosis


Are you one of seven million women in the United States with endometriosis? If so, you may also be struggling with infertility. Endometriosis is a female reproductive disorder characterized by pelvic pain, inflammation and vaginal ...

bleeding. This painful condition can affect any female of menstruating age, although it is more likely to run in families. If you experience abnormal bleeding or pelvic pain, talk to your doctor. While there is no known cause, and no known cure for endometriosis, treatments do exist, including medications and surgery to reduce symptoms and restore fertility.

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.