Bleeding is one of the very common complications after tooth extraction, with a 5-10% chance of occurrence according to the literature, and its causes are multiple. There are several methods commonly used in medicine to stop bleeding: compression, dressing, caulking, tourniquet binding, suture ligation, electrocoagulation, etc., but the only method that can be used to stop bleeding after tooth extraction is local compression. The doctor will let the patient bite on the hemostatic gauze for 30-40 minutes to stop bleeding after tooth extraction, and after spitting out the gauze, the extraction wound is open, and the extraction socket can only rely on its own blood coagulation to form a blood clot to stop bleeding, but the local blood clot is not stable within 24 hours and can easily be affected by local or systemic factors to cause bleeding again. Some patients do not bite the hemostatic gauze tightly after tooth extraction, which may cause bleeding; some patients rinse their mouth after tooth extraction, which may cause the clot to fall off and bleed; some patients touch hard objects or eat hard food after tooth extraction, which may cause bleeding; hot water or hot food may also cause bleeding; repeated sucking of the tongue on the extraction socket may cause bleeding; sometimes there are small arteries passing through the extraction socket due to anatomical variation, which may rupture and bleed; some patients with hypertension Some patients with hypertension may bleed due to changes in blood pressure after tooth extraction; some patients have other systemic diseases such as chronic hepatitis, cirrhosis, hemophilia and other diseases that cause poor blood clotting, which may lead to bleeding. The clotting time of each person may vary individually, and the clotting time after tooth extraction varies from one tooth extraction to another. Some patients have clotted within a few hours after tooth extraction, while others still have red blood in their mouths for 2-3 days. What are the signs of bleeding after tooth extraction? If a large blood clot can be seen with the naked eye above the alveolar sockets and adjacent teeth after the procedure, with fresh active blood oozing from the sockets, it is considered possible that the tooth is bleeding after extraction. If only the saliva is red and there is a bloody taste in the mouth, but no large localized blood clots in the extraction sockets are seen, this is generally normal. Some patients are very nervous and frightened after observing bleeding, which is actually unnecessary. Even if there is bleeding, patients do not need to worry about anxiety, as the amount of bleeding after tooth extraction is generally not large and it is difficult to have serious consequences such as life-threatening hemorrhagic shock. It can be handled by contacting the treating doctor or going to the emergency dental department, and the disposal process is very simple. Patients can also use sterilized medical gauze (available at pharmacies) at home to compress again for 30 minutes and observe again, and no bleeding is sufficient. Note: Bleeding due to systemic causes such as hemophilia needs to be promptly addressed by a physician.