The decrease in menstruation is often related to the following factors: first, endocrine disorders, such as a decrease in estradiol secretion in the body, the endometrium will become thinner and the menstrual flow will decrease. Secondly, if the decrease in menstrual flow is caused by polycystic ovary syndrome, it is recommended to have an ultrasound examination. If the ovaries are polycystic, it is recommended to have a blood test for sex hormone 6 on the second or third day of menstruation and then give treatment according to the results. Thirdly, if the menstruation becomes less frequent, a history of uterine operations, such as curettage, curettage or abortion, which resulted in incomplete adhesions to the uterine cavity before the menstruation became less frequent, may also cause the menstruation to become less frequent, so a comprehensive clinical analysis is needed. If there is a decline in ovarian function, menstruation may also become less frequent, so it is important to do a clinical examination and then give appropriate treatment according to the results.