Endometriosis is a disease of unknown cause that primarily affects women of reproductive age.
The lining of the uterus, called the endometrium, is found outside the uterus. Endometriosis usually causes pelvic pain. This may include pain with menstrual periods, pain with intercourse, pain with urination or bowel movements, and generalized pelvic pain at other times in the cycle. Women with endometriosis have a higher risk of fertility problems and infertility may be the only symptom of this disease. Some women with endometriosis have normal fertility and no pelvic pain.