A woman’s body changes every day, and with menstruation presenting a certain cycle, only by mastering a woman’s normal physiology, she will not be ignorant in her normal life, when seeing a doctor, and can even guide women to better conception and contraception. The menstrual cycle is the time between the first day of two menstrual periods, usually 21 to 35 days, with an average of 28 days. However, this is not absolute and very few people have their own specific cycle of menstruation. The ovarian cycle is carried out according to a series of very sequential events, and the rhythm of the menstrual cycle is generally divided into four periods: 1. Menstrual period: the first 1 to 4 days of menstruation, of which the first day is slightly less menstrual volume, the second and third days are more, and the duration should generally not exceed 7 days, at which time attention should be paid to a nutritious and healthy diet, to keep the vulva clean, and never have intercourse at this time. Recently too long or too short, too much or too little menstruation are all menstrual disorders and need menstrual regulation treatment. Patients with gynecological infections mostly choose anti-inflammatory treatment at this time, which can achieve better anti-inflammatory effect. 2, the late menstrual period: the 5th to 13 days of the menstrual cycle, this is also the period of follicle growth, endometrial hyperplasia, generally thick about 2 ~ 3mm, after the clean menstruation vagina will secrete a certain amount of under the belt, under the belt thin and transparent. Many drugs is the 5th day of menstruation to start taking, when you can avoid the menstrual period. 3.Intermenstrual period: The 14th to 15th day of menstruation, this period is in the middle of two menstrual periods, that is, the ovulation period. If there is ovulation, the body temperature may suddenly increase by 0.3~0.5℃ from the lower value when the basal body temperature is measured. During ovulation monitoring, ultrasound will show the process of enlarged follicles in the ovaries until they disappear and are discharged. For women with normal menstruation, ovulation usually occurs 14 days before the next menstruation. The egg can survive for 1 to 2 days after ovulation, and the strongest fertilization ability is within 24 hours after ovulation, and the sperm can survive for 2 to 3 days in the female reproductive tract. If the follicles do not ovulate, medication can be used to promote ovulation. Some people have a small amount of vaginal bleeding during this period, which is called ovulatory bleeding, i.e. mid-menstrual bleeding, which refers to a small amount of bleeding between two normal menstrual periods, which can be accompanied by varying degrees of abdominal pain, or just coffee-colored discharge, which usually stops on its own in 2-3 days, up to 7 days. 4, premenstrual period: the 15th to 28th of the menstrual cycle, usually lasting 14 days, because after ovulation, the corpus luteum appears in the follicle, so also known as the luteal phase, the ovaries are influenced by luteinizing hormone, secrete luteinizing hormone, maintain the thickened endometrium, in order to facilitate the fertilization of the egg, if no fertilization of the egg, the endometrium will disintegrate, the menstrual cycle ends with the menstrual flow. The above is a brief introduction to the menstrual cycle, I hope to help women understand themselves better, in addition, many patients come to see the doctor, do not remember their own menstrual specifics, especially forget the time of their last menstrual flow, here to remind friends to see the doctor, usually pay attention to their own menstruation, bring down the situation, as well as to bring the results of the previous examination, in order to To better help the doctor’s diagnosis and reduce repeat tests.