The endometrium normally covers the surface of the uterine cavity. If, for some reason, the endometrium grows outside the uterine cavity, it becomes endometriosis. This ectopic endometrium is histologically surrounded not only by endometrial glands but also by endometrial mesenchyme. Functionally, it varies significantly with estrogen levels, i.e., with the menstrual cycle, but only some of it is affected by progesterone and can produce a small amount of “menstruation” and cause various clinical phenomena. Patients with endometriosis tend to have cold extremities and abdomen, which is more serious during menstruation, so prevention is the key to prevent endometriosis from occurring. 2. Pay attention to keeping yourself warm and avoid feeling cold. 3, during menstruation, prohibit all intense sports and heavy physical labor. 4.If endometriosis has been detected, you must pay attention to keep emotional stability and avoid overwork during menstruation or the middle of menstruation. Once the tension in the cystic cavity suddenly rises, the cystic wall will rupture and acute abdomen will be formed. 5. Try to do abortion and scraping as little as possible and do family planning. 6.Menstrual period must do a good job of their own health care, pay attention to control their emotions, do not sulk, otherwise it will lead to endocrine changes. 7, women must eliminate sexual life during menstruation. 8, (1) Prevention of menstrual blood reflux: Some congenital or acquired diseases that cause poor drainage of menstrual blood, such as hymenal atresia, vaginal atresia, cervical stenosis, uterine malformation (especially stumpy uterus), extreme retroflexion of the uterus, etc., can cause poor flow or retention of menstrual blood, resulting in the reflux of menstrual blood into the pelvis, planting and development of endometriosis. Therefore, these diseases should be examined and treated early. Those with congenital abnormal development of reproductive organs should be treated surgically at the age of menarche after menstruation to avoid unnecessary vaginal examinations and sexual intercourse to prevent endometriosis. (2) Prevention of endometriosis to avoid endometrial implantation caused by surgical operation: ① Pay attention to protect the wound during cesarean operation to avoid bringing the endometrium into the incision for implantation. ②Avoid sudden reduction of negative pressure during abortion to prevent endometrial reflux into the pelvis. ③Tubal aeration and fluidization and hysterosalpingography should be performed 3 to 7 days after menstrual purification.