A person with normal blood clotting function will not bleed a lot from a tooth extraction. Normally the bleeding from the extraction socket stops 5 to 15 minutes after the tooth is extracted and a blood clot is formed. After tooth extraction, the doctor will stuff a cotton ball in the wound and let you bite it for half an hour and then spit it out. Don’t underestimate this cotton ball, it is the key to stop bleeding and prevent infection after tooth extraction. The cotton is sterilized and can be gently bitten to stop the bleeding and prevent the saliva from soaking into the wound, which helps the blood clot in the wound to clot and promote the wound healing. So don’t rush to leave the hospital after tooth extraction, make sure to bite the cotton ball and wait for half an hour to pass, spit it out and let the doctor check if it is still bleeding. If there is still significant bleeding, it is called bleeding after tooth extraction. Most of the time, it is caused by local reasons such as residual inflammatory granulation tissue in the socket, soft tissue tear, clot dislodgement, rupture of small blood vessels in the socket, etc. The doctor will make timely treatment to stop the bleeding. There are also a few cases caused by systemic diseases such as coagulation dysfunction, which require the patient to give the relevant medical history to the doctor before the extraction, so that the doctor can judge whether you are suitable for the extraction. Then there are ladies who bleed relatively longer during their menstrual period. It is better to avoid tooth extraction during menstruation. The most important prevention of tooth extraction complications is not to extract teeth during the acute infection period. The most common infection in the wound after tooth extraction is “dry socket”, the incidence of which is reported to be about 10% in China. How to prevent it from happening? The key is still the small ball of cotton mentioned before, and you should bite it for 30 minutes, but it is definitely not better to bite it for as long as possible, because the saliva will enter the wound through the cotton ball and it will be easily infected. Also, do not rinse your mouth vigorously for the blood that may ooze out of your mouth, keeping the blood clot in the extraction socket. Before tooth extraction, you should inform the doctor of your personal health condition, and tooth extraction is not suitable if you have the following conditions: 1. Patients with serious cardiovascular diseases and blood pressure above 180/100 mmHg, patients with bleeding disorders such as hemophilia and primary thrombocytopenic purpura; malignant tumors and psychiatric attacks should avoid tooth extraction; before the symptoms of diabetes are controlled; after strenuous exercise, labor and alcohol consumption 2. For children, if the milk teeth are not loose before the age of 6 but have dental lesions, they should be treated and should not be easily extracted; 3. declining and poor compensatory function, in addition to confirming that the physical condition allows the surgery, it is also recommended that elderly people, especially senior citizens over 70 years old, should preferably be accompanied by their family members when having a tooth extraction. Before tooth extraction, it is recommended to get enough sleep and eat as usual. If the tooth or root with inflammation is being extracted, antibiotics can be started 2 days before the extraction to prevent postoperative infection. Before tooth extraction, you should carefully brush and rinse your mouth to clean your mouth, and for patients with more calculus, it is recommended to remove it before extraction.