Endometriosis is a condition in which the tissue that behaves like the cells lining the uterus (endometrium) grows in other areas of the body, causing pain, irregular bleeding, and possible infertility. The tissue growth (implant) typically in the pelvic area, outside of the uterus, on the ovaries, bowel, rectum, bladder, and the delicate lining of the pelvis. However, the implants can occur in other areas of the body, too.
The cause of endometriosis is unknown, but there are a number of theories. One theory is that the endometrial cells loosened during menstruation may " backup " through the Fallopian tubes into the pelvis. Once there, they implant and grow in the pelvic or abdominal cavities. This is called retrograde menstruation. This happens in many women, but there may be something different about the immune system in women who develop endometriosis compared to those who do not get the condition.
Endometriosis is a common problem . Sometimes , it may run in the family. Although endometriosis is typically diagnosed between ages 25-35 , the condition probably begins about the time that regular menstruation begins.