Viral labyrinthitis is one of the most unpleasant infections you can get.

The labyrinth is a system of narrow fluid-filled channels in the inner ear, which is involved in the detection of body movement, helping to control balance and posture.

Infection of the labyrinth by a virus (or less commonly a bacteria) can cause inflammation of the delicate structure and lead to intense symptoms. Viral labyrinthitis usually strikes someone out of the blue, often as part of an epidemic.

Vertigo (which people often describe as dizziness) can develop very suddenly - everything spins around, or moves up and down in front of you. This is followed by nausea, vomiting, sweating and an urgent need to lie down. In fact, lying down very still with eyes closed is probably the only way to get relief without taking medication. Often the virus also causes symptoms such as ringing or buzzing in the ears (known as tinnitus) and headache.

The balance mechanisms within the inner ear are irritated by the infection. This causes the body to receive irregular and mixed-up messages about its position, so it's not sure where it is. It's similar to a severe bout of seasickness, but much worse.

Treatment involves measures to calm the symptoms down, while the body combats the virus. This includes anti-sickness medication that in the later stages can be taken as tablets. But early on, because of the vomiting, it's better to take the medicines through a different route, either injection or rectal administration, or via medicine that dissolves in the mouth. Taking plenty of liquid little and often enables dehydration to be avoided, without upsetting the stomach.

The symptoms usually last between one and three weeks and, by all accounts, it's a very disabling illness. Fortunately, it's usual to make a full recovery.

This article was last medically reviewed by Dr Trisha Macnair in April 2008