Endometriosis is a medical condition where tissue similar to the lining of the uterus, known as endometrium, grows outside the uterus. This can lead to severe pain, especially during menstruation, and may also cause fertility issues. The exact cause of endometriosis is still unknown, but it affects millions of women worldwide. Symptoms of endometriosis can vary, but common signs include pelvic pain, heavy periods, and pain during intercourse. Diagnosis often involves imaging tests or surgery. Treatment options range from pain management to hormonal therapies and, in some cases, surgery to remove the excess tissue.