Tooth extraction is a surgical procedure that is small but carries certain risks. Therefore, before tooth extraction, patients should truthfully inform the doctor of their health condition and medical history, and need to make appropriate preparations. Hypertension: If the blood pressure is higher than 180/100mmHg, you should first adjust and take antihypertensive drugs under the guidance of a cardiologist to lower it to below 160/90mmHg and make an appointment for cardiac monitoring for tooth extraction. Otherwise, cardiovascular accidents can easily be triggered and life threatening. Heart disease: frequent and frequent angina pectoris and 6 months of internal infarction should be suspended for tooth extraction. Patients with wind heart disease should take antibiotics before tooth extraction. Hematologic diseases: teeth should be extracted with caution under the guidance of hematologists and oncologists. Patients with chronic anemia with hemoglobin higher than 6 grams or more can have their teeth extracted. Patients with acute leukemia should suspend tooth extraction. Diabetes: Morning fasting blood sugar should be controlled below 8.88 mmol/L Pregnancy: It is recommended that young women should have oral system examination before pregnancy and extract wisdom teeth that may cause harm. Otherwise, pregnancy is very likely to cause pericoronitis in wisdom teeth. The first trimester of pregnancy is prone to miscarriage, the second trimester is prone to premature birth, and the middle trimester is relatively safe, but it is still recommended to avoid tooth extraction during pregnancy as much as possible. Menstrual period: It may cause compensatory bleeding, and it is advisable to suspend tooth extraction during the first few days of menstruation.