Your doctor will diagnose vertigo based on your description of what you are feeling. Vertigo can be divided into two major categories, peripheral vertigo and central vertigo.
Peripheral vertigo, which is much more common, includes benign positional vertigo, labyrinthitis and Ménière's disease. Positional vertigo is diagnosed when moving the head causes the vertigo and returning the head to a neutral position relieves symptoms. Labyrinthitis and Ménière's attacks usually come on abruptly and last from a few hours to a couple of days. There may be intense nausea and vomiting and variable hearing loss.
Central vertigo is a more serious problem in the cerebellum (back part of the brain) or brain stem.
Your doctor will evaluate your eye to look for abnormal jerking movements (nystagmus). The pattern of your eye movements may help to determine if the problem is peripheral or central. Usually, no further testing is needed unless your doctor suspects you have central vertigo. If central vertigo is suspected, your doctor will order a computed tomography (CT) scan or magnetic resonance imaging (MRI) of your brain.