Sudden dizziness can be seen in many cases.1. It is more often caused by an increase in blood pressure, which can be caused by emotional stress or anger. When blood pressure increases, dizziness, headache, and in severe cases, nausea and vomiting can also occur. It is recommended to take oral antihypertensive medication regularly and avoid the causes of increased blood pressure. 2. cerebral ischemia occurs, mainly due to the lack of blood supply to the brain, the patient has brainstem or cerebellar ischemia, dizziness can occur, and in severe cases, it can be accompanied by visual rotation, nausea, vomiting and panic. 3. Meniere’s syndrome or vestibular The occurrence of neuronal inflammation. Patients with Meniere’s syndrome have a history of recurrent dizziness, which can be triggered by poor sleep or a cold, and can be accompanied by ear congestion. Patients with vestibular neuronitis have a history of dizziness with nystagmus after a cold.