1. Bloody malignant fluid: named because of the large amount of blood, bright red, large amount, sometimes with small blood clots. Microscopically, a large number of red blood cells, necrotic meconium and a small amount of fetal membranes are seen. Bloody malignant dew lasts less than 3 days. The bleeding gradually decreases and the plasma increases, transforming into plasma malignant fluid. 2. Plasma malignant fluid: named because it contains a lot of plasma, with a light red color. Microscopically, more necrotic meconium, uterine exudate, cervical mucus, a small amount of red and white blood cells, and bacteria are seen. The plasma malodex lasts for 4-14 days, then the plasma gradually decreases and the number of white blood cells increases, turning into white malodex. 3. White malodex: It is named because it contains a large number of white blood cells and has a white color, with a viscous texture. Microscopically, a large number of white blood cells, necrotic meconium, epidermal cells and bacteria can be seen. The white nightmare lasts about 3 weeks. Although every woman has malignant dew, the amount discharged varies from person to person, with an average total of 500 to 1000 ml. The duration of continuous discharge varies from woman to woman. Normal women usually need 2 to 4 weeks, while a few women can continue for 1 to 2 months. When the child breastfeeds, sucking on the nipple can cause reflex uterine contractions, which facilitates the discharge of the dew in the uterine cavity. Therefore, if you still have bloody nightmare 21 days after delivery, you should go to the hospital to find out what the reason for this bloody nightmare is, whether it is because of poor uterine regeneration or because there are new signs of bleeding. Depending on the situation, the doctor will do a detailed physical examination and related ultrasound to further confirm the diagnosis, and then choose a different treatment plan according to the situation.