The causes of sudden onset of vertigo, tinnitus, nausea, and vomiting are as follows: 1. Inner ear fluid buildup triggers clinical manifestations of recurrent rotational vertigo, fluctuating hearing loss, tinnitus, and a sense of ear stuffiness, lasting from a few minutes to 24 hours, with natural relief of symptoms; 2. Sudden deafness can be accompanied by varying degrees of vertigo, mostly rotational vertigo with nausea and vomiting, which can occur simultaneously with deafness or before or after the onset of deafness; 3. Posterior circulation ischemia, often manifesting as vertigo, vomiting, and other symptoms.