Show accessibility tools About us Work with us News Contact us Patients and visitors Our hospitals Our services Professionals Research UCLH Charity General information about Endometriosis HomeOur servicesFind a service (A-Z)Women's HealthGynaecologyEndometriosisGeneral information about Endometriosis In this section FAQ's General information about Endometriosis Medical treatment for endometriosis Surgical treatment for endometriosis Endometriosis is a condition where tissue similar to the lining of the womb (uterus) is found elsewhere in the body. It is most commonly found in the pelvis (in or on the ovaries, behind the uterus, in tissue that holds the uterus in place and on the bowel and the bladder) but it can be found in other locations such as the chest cavity, lungs, abdominal wall scars and the navel. Endometriotic tissue may be located on the surface of organs and over the lining of the abdominal cavity (peritoneum). It may infiltrate deeper into the structures or may form cysts within the ovaries. These cysts are known as ‘chocolate cysts’ or endometriomas, which may be identified by an ultrasound scan. Every month, if a woman is not pregnant, the lining of the womb breaks down and is shed as a menstrual period. The endometriotic tissue (endometriosis) goes through a similar cycle and bleeds during menstruation. This may cause pain during periods, inflammation and scarring. The scarring can cause organs or structures to stick to each other and this may distort the normal anatomy. Anatomical distortion of the pelvic organs may cause difficulty in becoming pregnant. Deep endometriosis tissue and scarring can sometimes form small lumps and these are called ‘endometriotic nodules’. These nodules can be very tender and painful to touch. Scarring and nodules of endometriosis may cause some women to experience pain during sexual intercourse. Who is affected by endometriosis? How is endometriosis diagnosed? Other gynaecology services Select a service Colposcopy Differences in Sex Development Endometriosis Familial cancer clinics Female Genital Mutilation (FGM) Clinic Fertility and reproductive medicine laboratory GP Gynaecology Ultrasound Service Gynae-oncology Gynaecology diagnostic and treatment unit Intrauterine Insemination (IUI) London Complex Mesh Centre Paediatric gynaecology Reproductive medicine unit Urogynaecology Follow us on: Contact us Media and communications Support our Charity UCLPartners Terms & conditions Become a member Call 111 Accessibility Cookies & privacy