Vertigo, what is it?

Vertigo is a hallucination of movement,arising from problems within the vestibular portion of the inner ear.
The world spins about the patient, or the patient feels there is moving in space.
Dizziness is a giddy or swimming  sensation ,and is not vertigo.
Any disorder, tumor, infection or trauma causing a unilateral decrease in vestibular function may cause vertigo.