Numbness at the root of the tongue may be caused by the following types of diseases: First, diseases of the nervous system, such as having cerebral infarction, cerebral hemorrhage or cerebral thrombosis, because the nerves of the tongue come from the hypoglossal nerve, the linguopharyngeal nerve and the facial nerve emanating from the brain, etc. If the brain has hemorrhage, infarction and other cerebral neuropathy, it can affect the innervated tongue nerves, including the motor and sensory nerves. If the sensory nerve is damaged, it will produce abnormal sensation, which may lead to numbness of the tongue root. Secondly, it may be due to neurotrophic disorders, such as neurological dystrophy or neurological atrophy, because the sensory nerves innervating the tongue are facial nerve and linguopharyngeal nerve, if one of these two nerves is dysplastic or malnourished, it will become dysfunctional, and it will produce numbness of the tongue root.