There are many reasons for sudden dizziness, spinning and vomiting in sleep, if it occurs during turning over, it should be considered to be caused by otoliths, because the dislodged otoliths will stimulate the cell membrane of the semicircular canal when the head position changes, which will lead to episodes of dizziness, spinning and vomiting. The symptoms usually last no more than 1 minute and can be relieved when the head position is fixed. If the dizziness, spinning and vomiting are not relieved, posterior circulation ischemia should be considered. This is because the vestibular nucleus is stimulated by the slowed blood flow in the basilar artery bilaterally, and the patient will experience dizziness, spinning, nausea and vomiting. Patients with cervicogenic dizziness may also have this severe symptom due to improper sleeping position that causes discomfort in the neck.