Endometriosis is one of the common uterine diseases in women, which affects the normal life of many women and causes serious problems to many women. Endometriosis can also cause infertility in women, which is a very serious harm to women. The following will give you a detailed description of how endometriosis arises. The uterus plays the most important role in reproductive physiology and reproductive endocrine function, and its functions include: menstrual function, storage and transportation of sperm, pregnancy and egg placement, conception and delivery of a fetus. If there is a problem with the uterus, such as the occurrence of endometriosis, it can lead to a series of diseases, including the occurrence of female infertility. 1. Experts in endocrine dysfunction point out that ectopic endometrium, regardless of its source, has growth changes related to ovarian endocrine secretion, with estrogen promoting growth and progesterone inhibiting it. Most patients with endometriosis are clinically found to be progesterone deficient, thus contributing to its development. 2. Defective immune defense function Defective immune defense function is an important cause of endometriosis. Experts say that the endometrium that flows backwards into the abdominal cavity with menstrual blood is like a foreign body that activates the immune system in the body, mobilizing a large number of immune cells and body fluids to surround and eliminate it, and if the body’s immune function is defective, it will develop into endometriosis. 3, medical endometrium transplantation medical endometrium transplantation is also one of the causes of endometriosis, is an artificial cause of endometrium transplantation to certain parts of the uterus, mostly seen in the process of caesarean section, early and mid-term pregnancy scraping, perineal lateral incision during childbirth, abortion, etc. 4, menstrual blood reflux, endometrium implantation female menstrual period, menstrual blood from the uterus, vaginal discharge outside the body is downstream However, a small part of menstrual blood or for other reasons interspersed with shed endometrial fragments, flowing from the fallopian tube into the abdominal cavity, planted in the surface layer of the pelvic organs to form endometriosis lesions, which is the main reason. Therefore, menstrual blood reflux and endometrial implantation also contribute to the development of endometriosis. In addition, people with a family history of the disease are also more prone to endometriosis, with genetic factors included.