With endometriosis, tissue similar to the tissue that normally lines the inside of your uterus grows outside your uterus. Endometriosis most commonly involves your ovaries, fallopian tubes and the tissue lining your pelvis. Rarely, endometrial tissue may spread beyond pelvic organs. Endometriosis can cause pain that is sometimes severe, especially during menstrual periods.
While ovarian cancer occurs at higher-than-expected rates in women with endometriosis, the overall lifetime risk is low. Some studies suggest that endometriosis increases that risk, but it's still relatively low. Endometriosis is not considered a risk factor for ovarian cancer.
However, endometriosis can cause fertility problems. Approximately one-third to one-half of women with endometriosis have difficulty getting pregnant.
Learn more about endometriosis, including the causes and risk factors, as well as the possible complication of impaired fertility.