Self-perceived tongue inflexibility during speech may be related to cerebrovascular diseases such as cerebral hemorrhage and cerebral infarction, as well as infections, intracranial occupying tumors, or motor neuron disease. 1. Cerebrovascular diseases: If there is a slight cerebral hemorrhage, it can cause contralateral central facial paralysis, and the tongue is inflexible or appears to be stretched out to one side when speaking. Cerebral infarction can cause arterial occlusion, which can also lead to centralized tongue paralysis, unclear speech and tongue inflexibility. 2. Infection: Herpes simplex virus infection, resulting in facial nerve edema and demyelination, can cause peripheral facial paralysis, facial expression muscle paralysis, and tongue numbness and inflexibility when causing hypoglossal nerve palsy. 3. Tumor: intracranial space-occupying tumors or metastatic tumors can cause neurological deficits and slurred speech. 4. Motor neuron disease: if there is progressive medullary palsy, there may be atrophy of tongue muscle, muscle bundle tremor, and there may be speech dysarthria and other manifestations. If you feel that your tongue is not flexible when you speak, it is recommended that you go to a hospital specialist immediately, and after clarifying the cause of the disease through the relevant clinical manifestations and imaging examinations, you will be treated according to the cause and the symptom.