The main reasons for numbness of the mouth and tongue are as follows: 1. Ask the patient if there is hypertension, diabetes, cerebral infarction, such as acute cerebral infarction or cerebral hemorrhage, especially brainstem infarction after bleeding compression of the nerve appears numbness of the mouth and tongue, you need to do a cranial CT or MRI. 2. Ask the patient if there is a history of facial neuritis, because the facial nerve is a mixed nerve, the main The main sensation is the innervation of the taste sensation in the front 2/3 of the tongue. If the facial nerve is damaged, numbness of the tongue and loss of taste sensation may occur, and some may have numbness of the mouth. 3. Ask the patient if he has eaten eggs or drugs or food containing lead and mercury for a long time, as long-term oral intake of food or drugs containing lead and mercury can easily cause poisoning, which manifests as nerve damage and numbness of the mouth and tongue.