Early menstruation is mainly due to changes in hormone levels in the body, and menstruation is formed mainly due to a sudden drop in estrogen and progesterone, resulting in the stripping of the uterine lining, leading to bleeding and the discharge of the lining. If your menstruation was normal in the past, and then suddenly your menstruation starts more than a week earlier, it may be a sign that your ovarian function is declining. During menstruation, you should rest more and avoid exertion, quit smoking and drinking, eat less cold food to prevent menstrual discomfort or prolong the menstrual period, avoid sexual intercourse, and change underwear and sanitary napkins to avoid infections of the reproductive system. Menstrual blood is a good culture medium for bacteria and viruses, it is easy for bacteria to breed and thus reproductive infections occur, and serious cases may lead to adhesion of the fallopian tubes and the uterus and lead to infertility.