If the period is suddenly shortened from 7 days to 3 days, there is a significant decrease in volume. If you are married or have a history of sexual intercourse, it is important to exclude the possibility of pregnancy. If pregnancy has been ruled out, it is possible that the shortening of the period may be due to recent exertion or the consumption of cold food or cold drinks. In addition, if you have taken oral contraceptives, the menstrual flow may be reduced and the duration of menstruation may be shortened, so we need to analyze the clinical history comprehensively. It is recommended that women should try to lead a regular life, keep a good rest and rest schedule, and maintain a good mood to make their emotions stable. This will reduce the possibility of endocrine disorders in clinical practice and prevent menstruation from being affected accordingly.