Tooth extraction should be done with caution in the following cases: 1. Hypertension: Patients with high blood pressure should first control their hypertension before considering tooth extraction, and should also be done with caution if they suffer from organic damage to the heart, brain and kidneys. 2. Heart disease: Patients with heart disease who have had a myocardial infarction within 6 months; or who have recently had an attack of angina pectoris; or who have congestive heart failure, etc. should not have their teeth extracted. 3. Hematological diseases: Patients with hemophilia, thrombocytopenia and leukemia may have their teeth extracted rashly, which may cause more than bleeding and even endanger their lives. 4. Diabetes: Patients with diabetes are prone to wound infection and aggravation of diabetes after tooth extraction; diabetes should be controlled before tooth extraction and antibiotics should be used to prevent infection before and after tooth extraction. 5. Hepatitis and cirrhosis: Those with obvious damage to liver function should be treated with liver protection first and extraction should be performed only after liver function is basically normal because the coagulation mechanism in their bodies is affected. 6. Pregnant women: Tooth extraction during the first three months of pregnancy is prone to miscarriage, while tooth extraction during the second three months is prone to premature birth, so it is safer to extract teeth during the fourth, fifth and sixth trimesters of pregnancy. 7. Hyperthyroidism: Patients should have their teeth extracted only after their hyperthyroidism has been controlled. 8. Kidney disease: tooth extraction should be suspended for all kinds of acute kidney disease. For various chronic kidney diseases, the degree of kidney damage should be determined before deciding whether tooth extraction is possible. 9. Fasting: Due to tension, fasting can easily cause fainting due to hypoglycemia and is not suitable for tooth extraction.