The menstrual cycle, or menstrual cycle, is the period between the first day of menstruation and the first day of the next menstruation, which is normally 21-35 days, with an average of 28 days. However, depending on the physical differences of different women, some women have a menstrual cycle of 21-45 days, but as long as one’s cycle is regular and stable, it is a normal menstrual cycle. If the menstrual cycle is less than 21 days, it is called frequent menstruation, and if the menstrual cycle is greater than 45 days, it is considered scanty menstruation. Most menstrual irregularities are caused by endocrine disorders, and some of them are caused by adverse emotional factors, which do not require much treatment. However, if it is irregular for a long time, you should pay attention to it and go to the hospital in time for relevant examination to find the cause of irregular menstruation and to carry out symptomatic treatment so as not to delay the condition and cause more damage to your health. In addition, there are many precautions to take during menstruation, such as not eating cold and stimulating foods, not having intercourse during menstruation, and ensuring sufficient sleep and relaxation, as well as keeping the vulva clean to avoid affecting the stability of the menstrual cycle.