After cesarean section, the vagina will exclude some blood, which is the shedding of uterine metaphysis after delivery, especially the metaphysis of the placenta attachment, containing blood, necrotic metaphysis and other tissues discharged through the vagina is called post-partum malodor, which is a physiological change. Dew includes the uterine lining, blood stasis, and mucus. Dew has a bloody taste but no odor, and its color and contents change over time, usually lasting 4 to 6 weeks. Dew is divided into three types according to its contents and duration: Red Dew (Bloody Dew): the most frequent within 3-4 days after delivery, lasting for 1 week; it is more voluminous, bright red in color, and contains a large amount of blood, small clots, and necrotic meconium tissue. Plasma Dew: after one week and up to half a month after delivery, the amount of blood decreases and contains meconium, mucus, vaginal secretions and bacteria, which makes the dew become a light red plasma. White Dew: After half a month and up to four weeks, it no longer contains blood, but a large number of leukocytes, meconium, epidermal cells and bacteria, making it sticky and whiter in color. It lasts for three weeks. Excessive Dew: Generally speaking, the evil dew can be discharged within three weeks after delivery, and if it is still dripping for more than three weeks, it is called “inexhaustible dew”. However, in fact, women who still have a small amount of bleeding five weeks after delivery can often be seen in the clinic, while the examination can be without any abnormality. If there is not much discharge, no odor, no abdominal pain, fever and other abnormal symptoms, you can continue to observe for the time being, and go to the hospital for a review 6 weeks after delivery. Common causes of poor discharge: retained placenta, poor recuperation, poor healing of surgical incision, endometritis, etc. The cause can be clarified through ultrasonography and blood test, so as to find the cause of the disease and provide targeted treatment.