Endometriosis is a health condition experienced by people with uteruses whereby tissues that normally line the inner uterus grow outside this organ. This tissue typically grows throughout the female reproductive system, including on the ovaries, fallopian tubes, and pelvis. In rare circumstances, tissue growth may extend beyond the pelvic organs.
Just like the tissue growing inside the uterus, the tissue that grows through endometriosis thickens and breaks down during a normal menstrual cycle. However, it doesn’t have a way to leave the body so it becomes trapped. It can irritate tissue near it and cause scars, cysts, and adhesions. It can also trigger pain, especially during periods, and fertility issues. Health professionals aren’t sure what causes endometriosis.