The normal endometrium grows on the surface of the uterine cavity, but due to some factors it grows to parts outside the uterine cavity, such as the ovaries and cervix, causing a series of symptoms such as menstrual pain and infertility, a phenomenon called endometriosis, which is a disease of the uterus. It is also the main cause of infertility in women today. The endometrium is very important for a woman to get pregnant because the fertilized egg formed by the union of sperm and egg needs to be laid on the endometrium. If there is endometriosis, then the fertilized egg will not be able to be laid on the endometrium and the endometrium will not be able to provide nutrition for the early development of the fertilized egg, thus leading to infertility. In women with endometriosis, the endometrium grows outside of the uterine cavity, so there are a series of clinical symptoms such as severe abdominal pain and decreased or increased menstrual flow during the process of shedding. The cause of endometriosis in women is unclear and may be related to backflow of menstrual blood, multiple abortions or induced abortions, endocrine disorders, and other factors. Women who are diagnosed with endometriosis need to go to the obstetrics and gynecology department of a hospital in a timely manner and can be treated through medication or surgery.