Endometriosis is the abnormal growth of cells (endometrial cells) similar to those that form the inside of the uterus, but in a location outside of the uterus. Endometriosis is most commonly found on other organs of the pelvis.
Who is affected by endometriosis?
Endometriosis affects women in their reproductive years. The exact prevalence of endometriosis is not known, since many women may have the condition and have no symptoms. Endometriosis is estimated to affect over one million women (estimates range from 3% to 18% of women) in the United States. It is one of the leading causes of pelvic pain and reasons for laparoscopic surgery and hysterectomy in this country. Estimates suggest that 20% to 50% of women being treated for infertility have endometriosis, and up to 80% of women with chronic pelvic pain may be affected.
What causes endometriosis?
The cause of endometriosis is unknown. One theory is that the endometrial tissue is deposited in unusual locations by the backing up of menstrual flow into the Fallopian tubes and the pelvic and abdominal cavity during menstruation (termed retrograde menstruation). The cause of retrograde menstruation is not clearly understood. But retrograde menstruation cannot be the sole cause of endometriosis. Many women have retrograde menstruation in varying degrees, yet not all of them develop endometriosis.
Another possibility is that areas lining the pelvic organs possess primitive cells that are able to grow into other forms of tissue, such as endometrial cells. (This process is termed coelomic metaplasia.)
What are endometriosis symptoms?
Most women who have endometriosis, in fact, do not have symptoms. Of those who do experience symptoms, the common symptoms are:
- Pain (usually pelvic) that usually occurs just before menstruation and lessens after menstruation
- Painful sexual intercourse
- Cramping during intercourse
- Cramping or pain during bowel movements or urination
- Painful pelvic exam
Other symptoms that can be related to endometriosis include:
- lower abdominal pain,
- diarrhea and/or constipation,
- low back pain,
- chronic fatigue
- irregular or heavy menstrual bleeding,
- painful urination, or blood in the urine