What're the common causes of random dizziness?

Ears drugs migraine: Infection or dysfunction of the ear can cause a for of vertigo and dizziness which can be severe. Medications and drugs will often have side effect of dizziness. One of the more common symptoms of migraine headaches is dizziness and nausea. Meniere's disease affects the inner ear, and Dilantin toxicity affects the cerebellum and brainstem. Ear infections can cause severe dizziness.