Nerve block is a common treatment method in clinic, with good effect and no side effect under standard operation, but if it is not operated properly, it may cause nerve damage, blood vessel damage, and a small number of people may have allergic reaction. 1. Nerve damage: Some people may suffer nerve damage, such as nerve numbness and abnormal sensation, because of the wrong location of the needle when performing nerve block surgery. 2. Vascular damage: If the doctor operates in an incorrect position during the operation, it may cause damage to the blood vessels, such as local hematoma. 3. Allergic reaction: nerve block patients need local injection of anesthesia drugs, and people who are allergic to injected drugs may have allergic reactions. Any treatment may have certain risks, usually in the correct standardized operation can greatly reduce the incidence of risk. Nerve blocks should be performed in an authorized hospital.