If the number of days of menstruation becomes shorter, for example, it used to be 7 days clean, but later becomes 3 days clean, then it will inevitably lead to a decrease in the volume of menstruation, which is common in clinical practice for the following reasons: 1. due to endocrine disorders, which often lead to changes in the volume and duration of menstruation due to changes in hormone levels. 2. due to the development of endometrial tuberculosis, which can also lead to a decrease in the volume of menstruation and even the possibility of amenorrhea. 3. 3. A history of abortion, or a history of uterine surgery, or in general a history of uterine cavity manipulation, which leads to incomplete adhesions in the uterine cavity, resulting in shorter menstruation and reduced menstrual volume, in which case it is recommended to have a sex hormone test and ultrasound examination, and then give treatment according to the results.