Ménière’s disease is a disorder of the inner ear that causes severe dizziness (vertigo), ringing in the ears (tinnitus), hearing loss, and a feeling of fullness or congestion in the ear. Ménière’s disease usually affects only one ear."

Source : US National Institutes of Health, NIDCD

Attacks of dizziness may come on suddenly or after a short period of tinnitus or muffled hearing. Some people will have single attacks of dizziness separated by long periods of time. Others may experience many attacks closer together over a number of days. Some people with Ménière’s disease have vertigo so extreme that they lose their balance and fall. These episodes are called 'drop attacks'.”

[Source as above]

Ménière’s disease can develop at any age, but it is more likely to happen to adults between 40 and 60 years of age. The National Institute on Deafness and Other Communication Disorders (NIDCD) estimates that approximately 615,000 individuals in the United States are currently diagnosed with Ménière’s disease and that 45,500 cases are newly diagnosed each year."

[Source as above]

The symptoms of Ménière’s disease are generally thought to due to some kind of abnormalities in the fluid of the compartments of the inner ear - but as yet there is no direct explanation.

Triggers probably involves both genetic and environmental factors. Current theories include constrictions in blood vessels, viral infections and autoimmune reactions.

Also see : Labyrinthitisplugin-autotooltip__plain plugin-autotooltip_bigLabyrinthitis

"Labyrinthitis is an inflammatory disorder of the inner ear, or labyrinth. Clinically, this condition produces disturbances of balance and hearing to varying degrees and may affect one or both ears. Bacteria or viruses can cause acute inflammation of the labyrinth in conjunction with either local or systemic infections. Autoimmune processes may also cause labyrinthitis. Vascular ischemia may result in acute labyrinthine dysfunction that mimics labyrinthitis".