It is normal for a woman to have a menstrual period if the amount is low 1-2 days before and increases after 2 days, and the period can end within 7 days. Because a woman’s endometrial lining sheds very little during the first 2 days of her period because the hormone level has just dropped, the patient bleeds very little, the blood stays in the uterine cavity and in the vagina for a period of time to flow out, and the bleeding is mostly brown. If the patient has a very small amount within the first 4-5 days of menstruation, and the menstrual period is relatively long, more than 8 days is abnormal, consider that the patient may be luteal insufficiency, adenomyosis, uterine fibroids, lowering of the birth control ring and other causes, must be combined with the patient’s clinical symptoms and signs to determine the specific cause, for example, when the patient measures the basal body temperature, the body temperature rises and maintains less than 12 The onset of menstruation will occur in less than 12 days, suggesting that the patient has luteal insufficiency.