http://familydoctor.org/familydoctor/en/diseases-conditions/benign-paroxysmal-positional-vertigo.printerview.all.html
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American Academy of Family Physicians
Benign paroxysmal positional vertigo (BPPV) is a problem with the nerves and structure of the inner ear that causes you to suddenly feel dizzy. Read about the causes, symptoms, diagnosis and treatment of vertigo.