Vaginal bleeding occurs about one month after delivery, which may be postpartum dew or the return of menstruation. It is a clinical manifestation of the puerperium and is a physiological change. It can be bright red in color and usually lasts 4-6 weeks. The duration of discharge varies from woman to woman, from 2-4 weeks for normal women to 1-2 months for a few women. The return of menstruation after childbirth is related to whether the mother is breastfeeding, the length of time she breastfeeds, her age and the recovery of ovarian function. For those who are not breastfeeding, menstruation usually resumes in 6-10 weeks after delivery, and for those who recover earlier, menstruation may occur in one month after delivery. If you want to identify it clearly, it is recommended to go to the hospital for ultrasound examination after the blood volume decreases, and the diagnosis can usually be confirmed.