Endometriosis

Endometriosis is a chronic, estrogen-dependent inflammatory disease in which tissue that resembles the lining of the uterus (endometrium) is found outside the uterine cavity. It most often sits on the pelvic peritoneum, the ovaries, the uterosacral ligaments and the rectovaginal septum, but it can reach the bowel, the bladder, the ureters and, rarely, structures outside the pelvis. It is now understood as a chronic systemic disease rather than a simple pelvic problem. The mental model that makes the rest of the topic easy has three parts. 1. The tissue responds to hormones. Ectopic lesions respond to the monthly estrogen and progesterone cycle. Unlike the uterine lining, their blood and debris cannot leave the body, so each cycle feeds local inflammation. 2. Inflammation becomes scarring. Persistent inflammation leads to fibrosis and adhesions. Organs that should slide past each other become stuck together, and pain can be present outside the period as well as during it. 3. Treatment works by calming the hormone cycle or removing the tissue. Hormonal drugs lower estrogen effect or stop menstruation; surgery excises lesions. Neither cures the...