The reasons for a low menstrual volume and delayed menstrual cycle are as follows: 1. Endocrine disorders: If a woman has hyperprolactinemia, abnormal thyroid function or insulin resistance, polycystic ovary syndrome, many ovulation in this case are not normal, or there is no normal ovulation at all, so the women’s menstrual cycle is irregular, manifesting as frequent delays or non-arrival, amenorrhea. 2. Follicular problems. If there are no normal follicles or dominant follicles, the thickness of the endometrium may not thicken, manifesting as a thin endometrium or abnormal symptoms of low menstrual volume. 3, ovarian problems: low menstrual volume may also be caused by poor ovarian function or decline, which can be determined by testing the endocrine six or taking blood for AMH. 4, other: if a woman is combined with endocrine disorders, and combined with If a woman has a combination of endocrine disorder and uterine adhesions or scarring, it may also lead to low menstrual flow and delayed menstruation.