Sudden onset of dizziness, nausea and vomiting can be caused by the following possible conditions: 1. Benign positional vertigo, which is related to postural changes, and is often caused when patients get up, turn over or fall asleep in a lying or sitting position. The dizziness is accompanied by nausea and vomiting and lasts for a long time, from tens of minutes to several hours. 3. Cervical spondylosis, if the patient has cervical spondylosis with physiological curvature straightening, pulling the muscles of the back of the neck, often has episodes of dizziness, dizziness is not accompanied by visual rotation, can be accompanied by nausea, no other autonomic function reactions.