The main reasons why women have very little menstruation are as follows: 1. Decline in ovarian function, which causes a decrease in the amount of menstruation in women. The decline in ovarian function and the decrease in estradiol cause the endometrium to become thinner, leading to a decrease in menstrual flow. 2. A history of uterine operations, such as a patient who has had an abortion or diagnostic curettage, which causes damage to the endometrium, can cause incomplete adhesions in the uterine cavity, which can also lead to a decrease in menstrual flow in female patients. 3. The decrease in menstrual flow can be caused by certain diseases, such as polycystic ovary syndrome, endometrial tuberculosis, etc. 4, women’s excessive dieting, weight loss, resulting in a decrease in female estrogen secretion, malnutrition and lack of qi and blood will also lead to a decrease in female menstrual flow. 5, women usually do not have a regular life, do not pay attention to warmth during the period, like to eat cold food, etc., can lead to a decrease in female menstrual flow during the period.