If a patient suddenly develops dizziness, the following factors should be considered first: 1. Dizziness caused by insufficient blood supply to the cerebral arteries is most common in elderly patients. Head CT as well as head MRA can be improved to clarify whether there is evidence of intracranial ischemia, which can be treated with symptomatic circulation improving drugs. If the symptoms improve, the diagnosis is clear. 2. If the patient is young and suddenly develops dizziness, nausea, vomiting, accompanied by visual rotation, tinnitus and other symptoms, the most common consideration is Meniere’s disease, which is often referred to as vertigo, and can be treated with anti-dizziness symptomatic drugs, except for substantial diseases by improving head CT.