Definition of Meniere's disease:

Meniere's disease is a disorder of the inner ear affecting balance and hearing, characterized by abnormal sensation of movement (vertigo), dizziness, loss of hearing in one or both ears, and noises or ringing in the ear (tinnitus).

Causes, incidence, and risk factors:

The fluid-filled semicircular canals (labyrinths) of the inner ear, in conjunction with the cranial nerve VIII, control balance and sense of body position. Meniere's disease involves a swelling of part of the canal (endolymphatic sac). The endolymphic sac controls the filtration and excretion of the fluid in the semicircular canals.

The exact cause of Meniere's disease is unknown. In some cases, it may be related to middle ear infection (otitis media), syphilis, or head injury. Other risk factors include recent viral illness, respiratory infection, stress, fatigue, use of prescription or nonprescription drugs including aspirin, and a history of allergies, smoking, and alcohol use. There may be genetic risk factors as well.

About 100,000 people per year develop Meniere's disease.