Definition of Meniere's disease:

Meniere's disease is an inner ear disorder that affects balance and hearing.

See also: Vertigo

Causes, incidence, and risk factors:

The inner ear has fluid-filled tubes called semicircular canals, or labyrinths. The canals, along with a nerve in your skull, help interpret your body's position and maintain your balance.

Meniere's disease occurs when a part of the canal, called the endolymphatic sac, becomes swollen. This sac helps filter and remove fluid in the semicircular canals.

The exact cause of Meniere's disease is unknown. In some cases, it may be related to:

• Head injury
• Middle ear infection
• Syphilis

Other risk factors include:

• Allergies
• Alcohol use
• Fatigue
• Recent viral illness
• Respiratory infection
• Smoking
• Stress
• Use of certain medications, including aspirin

Genetics may also play a role.

Between 50,000 and 100,000 people a year develop Meniere's disease.