Menstruation is commonly known as menstruation, clinically known as menstruation, the first post-partum menstruation lasts for a long time without other symptoms, mostly normal phenomenon, if the menstruation lasts for more than eight days and the amount of menstruation is larger, then it is an abnormal phenomenon. The first menstruation after childbirth, because the hypothalamus-pituitary-ovary axis function has not yet fully normalized, hormone secretion is unstable, can not be normal ovulation, if this time the estrogen level is higher, it will contribute to the thickening of the uterine lining leading to a relative increase in the amount of menstrual bleeding, the duration of menstruation is long, this is a normal phenomenon. However, if the menstrual period lasts for more than 8 days and the menstrual flow is heavy, it is abnormal, which may be due to intrauterine residue, puerperal infection and other factors, and you need to go to the hospital in time and follow the doctor’s instructions for treatment.