To determine whether the menstrual flow is heavy or light, it is generally judged roughly based on the duration of menstruation and the number of tampons used. Normal menstrual flow is 20~60ml, less than 5ml is regarded as low menstrual flow, and more than 80ml is regarded as high menstrual flow, which can be estimated according to the duration of menstruation and the number of tampons used in life. 1. Duration of menstruation: the duration of menstruation is usually 2-8 days, with an average of 4-6 days. If the menstruation ends in 1-2 days after the onset of menstruation, the probability is that the menstruation is light, and if the menstruation lasts for more than a week, the probability is that the menstruation is heavy, but it is better to estimate it by combining it with the number of tampons used. 2. The number of tampons used: normal women use about 10-20 tampons for one menstrual period, if the number of tampons used is less than 10 and the menstrual period ends within 1~2 days, or even using pads, then it is judged to be menorrhagia; if the number of tampons used is more than 20, then it is judged to be menorrhagia. Excessive or scanty menstruation suggests that a woman may have certain diseases, which may also affect her fertility. It is recommended that women who have excessive or scanty menstruation go to a gynecologist for a clear explanation of the cause of menstruation and follow the doctor’s instructions for active treatment.