Endometrium is the tissue that lines the inside of the womb (uterus). It usually thickens during menstrual cycle in preparation for pregnancy and sheds off if pregnancy does not occur. Endometriosis is a condition where the lining of the endometrium forms outside the uterus. It is especially common among women in their 30s and 40s. The common symptoms are infertility, pelvis pain and pain that happens most often before and during menstruation. However, the majority do not display any signs and symptoms.

Some women may experience pain or cramps during or after sexual intercourse. Endometriosis may be suspected based on findings during physical examinations such as pelvic exam, imaging tests such as the ultrasound scan, although surgery may be required to confirm the diagnosis. Treatment includes medical therapies, medications and/or surgery.