A hard tongue, if sudden, is considered to be cerebrovascular disease, which can be seen in brainstem lesions or in anterior circulation lesions leading to damage to the linguopharyngeal vagus nerve, and the patient can develop a hard tongue and dysarthria. In severe cases, it can be accompanied by dysphagia, and the cause can be determined after CT or MRI of the head. A hard tongue with gradual onset and symptoms of dizziness and headache may be associated with intracranial occupational disease, including metastases and in situ tumors, and may be detected by CT or MRI. A hard tongue can also be seen in degenerative diseases, such as Parkinson’s disease, multiple system atrophy, and motor neuron disease. Due to degeneration resulting in damage to the glossopharyngeal nerve or abnormal muscle tone, patients may also present with a hard tongue, along with other clinical symptoms.