Sudden dizziness and unstable walking are caused by insufficient blood supply to the brain in mild cases, or acute cerebral infarction in severe cases. When this symptom occurs, it is recommended to immediately consult a hospital for a CT head examination, and after excluding cerebral hemorrhage, treatment for cerebrovascular disease to improve blood supply can be given. If acute cerebral infarction is considered to be the cause, the patient will have signs of neurological deficits, dizziness, and unsteadiness in walking, which are considered to be problems in the posterior circulation, such as infarction of the brainstem and cerebellum. In addition to these symptoms, the patient will also have positive signs such as inaccurate finger and nose and difficulty in standing with eyes closed on physical examination. If the dizziness is aggravated by changing the position, it is considered benign paroxysmal positional vertigo, which can be treated by manual repositioning.