Tooth extraction is the most common minor surgery performed in dentistry, but sometimes it can lead to accidents, undue damage and pain, and in severe cases, life-threatening. Therefore, it requires both physical and psychological preparation before tooth extraction. Many patients have anxiety and fear about tooth extraction, avoiding it because of nervousness and fear, or failing to cooperate with the dentist during the extraction process, or even fainting. Everyone should know the following precautions before tooth extraction: If the patient is accompanied by other systemic diseases, especially hypertension, coronary heart disease, etc., serious complications may arise as a result, and even life threatening. It is recommended that in addition to effective control of systemic diseases and physical condition meeting the requirements for tooth extraction, great attention should be paid to the mental preparation and psychological ability of the patient. Those with serious cardiovascular diseases and high blood pressure above 180/100mmHg. Patients with heart disease in general can have their teeth extracted as long as they do not show signs of cardiac insufficiency. 1. Bleeding diseases: Patients with hemophilia and primary thrombocytopenic purpura, for example, have a tendency to bleed because of the disorder of coagulation process in their bodies. If the bleeding is difficult to stop after tooth extraction, it will cause hemorrhage and life-threatening. As for patients with leukemia, since they are highly susceptible to infection, the incision after tooth extraction can also become a focus of infection, which can lead to serious systemic infection and is difficult to control. Therefore, when these patients suffer from dental disease, they should be treated conservatively and tooth extraction is contraindicated. 2. Menstruation, pregnancy and lactation: Women should, in principle, avoid tooth extraction during menstruation, because compensatory bleeding may occur in the tooth socket during menstruation. However, the extraction of loose teeth during menstruation does not affect the patient much. Some “deep-rooted” teeth, such as obstructed teeth or buried teeth, should be extracted after menstruation. According to some data, it is most appropriate for women to have their teeth extracted around the 10th day of their menstrual cycle, when the wound heals faster and bacterial infection is less likely to occur. Some people believe that no tooth extraction should be performed during pregnancy because it may lead to miscarriage. However, a lot of clinical practice shows that tooth extraction during the third to seventh month of pregnancy is safer and has no adverse effects on pregnancy.