Low menstrual flow in women is a warning against infertility; low menstrual flow in women may prevent the patient from conceiving or the fertilized egg from being laid and growing normally due to endometrial lesions, thus leading to infertility. Hypomenorrhea is a condition in which the menstrual cycle is normal, but the number of days of each menstruation is shorter than 2-3 days, the volume of menstruation is low, and the blood is dark purple or pink. The causes of menorrhagia are: 1. Hypothalamus and pituitary gland hypofunction: mostly due to mental factors, genetic or environmental factors, but also due to systemic diseases or long-term use of contraceptives. Due to the above factors inhibit the secretion of the pituitary gland to promote the secretion of glandular hormones and lead to menorrhagia. Also seen in congenital uterine dysplasia, because the uterus is very small, only a very small amount of endometrial shedding, the menstrual volume is also small. 2.Some gynecological diseases are common causes of menorrhagia: for example, endometrial tuberculosis destroys part or all of the endometrium to form scars, resulting in menorrhagia or even amenorrhea. 3, scraping surgery: especially after multiple abortions scraping surgery, due to excessive mechanical damage, resulting in the endometrium can not repair regeneration, or uterine cavity adhesions, can occur menorrhagia or even amenorrhea. 4, ovarian insufficiency: In the endometrial cells, there is a special type of particles called lysosomes, which are related to the amount of menstrual blood and bleeding time. If the level of estrogen and progesterone is high, there will be more lysosomal complexes, more bleeding and longer bleeding time. On the contrary, if the ovaries are underdeveloped and the amount of sex hormones is low, there will be less lysosomal complexes, less bleeding and shorter bleeding time.