The endometrium is the lining of the uterus, and generally the endometrium will come to menstruation when it reaches at least 8mm. It is recommended that women during menstruation pay attention to care, adjust diet and ensure sufficient rest. A woman’s menstruation is generally the shedding of the uterine lining, the average cycle is 28 days, due to the stimulation of the female body’s estrogen to the uterine lining, which will lead to the thickening of the uterine lining, most women in the uterine lining to grow to at least 8mm when the menstruation will come, if the uterine lining is too thin, it will not come to menstruation. Women who are menstruating should pay attention to their menstrual care, change sanitary napkins regularly, ensure the hygiene of the pubic area, and wash the pubic area in a timely manner. Menstruating women should also improve their diet and eat less spicy food, such as chili peppers and onions. In addition, menstruating women should try to rest and should not stay up late. Menstruation usually comes after the endometrium reaches at least 8mm, and women are advised to develop healthy habits to avoid delayed menstruation.