For 1-2 days after wisdom tooth extraction, it is normal to have a small amount of blood in the saliva because of the incision in the mouth, which can usually resolve on its own. If the bleeding is abnormal, large and bright red, it may be caused by dislodged blood clots, improper care, or elevated blood pressure. Prompt medical consultation is needed to take targeted treatment according to the specific etiology. 1. When cleaning the mouth, the water flow may be too large or improperly operated, which may dislodge the blood clot from the trabecular surface or the suture breaks and falls off, exposing the fresh trabecular surface, resulting in bleeding; 2. Improper postoperative care, spitting, rinsing, brushing, sucking on the extraction trabeculae and eating spicy and rough food within 24 hours of tooth extraction may stimulate the trabecular surface causing persistent bleeding; 3. Poor oral hygiene and gum and periodontal inflammation before tooth extraction may cause bleeding the day after surgery; 4. Bleeding caused by other diseases, such as reduced platelets, coagulation dysfunction and uncontrolled hypertension, may cause more than bleeding after tooth extraction surgery. Therefore, when there is bleeding performance on the second day after wisdom tooth extraction, you can first stop the bleeding by local pressure, and if the symptoms cannot be relieved, you should seek medical treatment in time. If the wound is too large, the wound needs to be closed. If the bleeding is caused by systemic factors, symptomatic treatment is needed to avoid delaying the condition.