Low menstrual flow at the age of 39 may be caused by endometrial damage after abortion or medical abortion, resulting in reduced menstrual flow due to uterine adhesions, or due to premature ovarian failure, resulting in thin endometrium and low menstrual flow, or due to endocrine disorder, which results in the absence of ovulation. The follicle development is small, the secretion of estrogen is low, the endometrium is thin, the menstrual flow will be reduced, you can check the sex hormone six and thyroid hormone on the third day of menstruation. If there are endocrine problems, treatment should be carried out according to the test results. If the ovarian function is premature failure, it can be diagnosed through endocrine tests. If the decrease in menstrual flow is due to abortion and there is no requirement for fertility, regular observation is possible and no treatment is needed.