The exact cause of endometriosis is unknown. Possible causes are:back-up of menstrual flow from the uterus through the fallopian tubes(retrograde flow) into the pelvis; direct transfer of endometrial cells during surgery(of the uterus)to other areas; presence of high levels of estrogen even after menopause; presence of primitive cells lining pelvic organs that are able to grow into endometrial tissue.
Attribution: Avallain