It is normal to bleed for half an hour after tooth extraction, and it is also normal to have blood in saliva within a day. Gums may be torn and tiny blood vessels in the alveolar fossa ruptured during tooth extraction, and pressure is needed to stop bleeding for half an hour after extraction, and cotton balls or gauze can be bitten to stop bleeding. After the extraction of large teeth with thick roots, the bleeding time is longer, and sometimes the gums need to be cut or flaps need to be turned to remove the bone when wisdom teeth are extracted, and sutures need to be closed to stop the bleeding after the extraction. Bleeding can be significantly controlled about half an hour after extraction. It is normal to have blood seepage within one day after extraction, if there is obvious bleeding more than half an hour, or there is still blood seepage after one day of extraction, it is necessary to timely follow-up treatment, and if necessary, to carry out the coagulation function test.