The sudden occurrence of vertigo while sleeping is as follows: First, benign positional vertigo, where patients suddenly experience vertigo when they turn over during sleep. The vertigo is obviously related to the change of position, and the dizziness is accompanied by visual rotation, nausea, vomiting, sweating and panic, etc. It lasts for a short time and can be relieved in 1-2 minutes, and is most obvious when turning over to one side. It is also called otoliths, a kind of vestibular peripheral vertigo. Secondly, cerebrovascular disease, in case of elderly patients, sometimes occurs during sleep, most commonly cerebellar or brainstem infarction. Sudden vertigo in a quiet state is the main manifestation, and physical examination can also reveal other signs such as ataxia, cranial nerve injury, and limb paralysis.