what is vertigo?

Vertigo, a symptom of a balance disorder, is the illusion of movement when no movement is present. This can be caused by a problem of the inner ear balance mechanisms, or by a problem in the brain. While usually harmless, vertigo can be a sign of a serious condition if accompanied by difficulty in speaking or walking, severe headaches, or double vision. Even when no other symptoms are present, it is always a good idea to consult a doctor. The same is true if the episodes worsen over time or if new symptoms appear.
Common causes of vertigo include the following:
Benign paroxysmal positional vertigo or BPPV, which is caused by an inner ear problem and is the most common cause of vertigo. BPPV is characterized by sudden and severe episodes that are nonetheless not serious.
Inflammation or infection of the inner ear, which can lead to hearing loss if not treated immediately.
Certain serious medical conditions, including multiple sclerosis and head or neck trauma.
Cerebellar hemorrhages, which cause vertigo because of decreased blood flow to the brain. In this case, vertigo is accompanied by more serious symptoms, such as difficulty walking and vision impairments.
Meniere disease, which often also causes ringing in the ear.
Severe migraines.