A 76-year-old man went to the hospital complaining that he had experienced vertigo for three years and that it had gotten worse in the last two to three months. What he meant by vertigo, he explained, was a sensation of "things in the house spinning," along with nausea lasting less than a minute. He felt fine if he stayed in bed and did not move. He did not have slurred speech, weakness of extremities or any other symptoms that might point to a neurological or brain problem.

He was first diagnosed with Meniere's syndrome, a mysterious disorder that causes severe vertigo, hearing loss and a ringing or other sensation in the ears. He was treated with the drug Diazide®. After that, everything had been fine until the past few months, when he had several new attacks of the same symptoms, but with more severe nausea and vomiting. He was now afraid that he was about to have another attack.

A series of tests revealed that instead of Meniere's Disease, the man was actually suffering from another illness called Benign Paroxysmal Positional Vertigo, or BPPV. Meniere's Disease and BPPV are the two most common causes of vertigo. While one can be mistaken for the other, as in this example, they are different diseases with different symptoms and different treatments.

Vertigo is not a disease in itself, but rather a symptom that can have any number of causes. The famous Alfred Hitchcock film notwithstanding, a fear of heights is not normally one of them. Vertigo is defined in Webster's dictionary as a feeling "in which the external world seems to revolve around the individual or in which the individual seems to revolve in space."(2) Occurring without warning, it comes and goes unpredictably and is often accompanied by nausea, vomiting and problems with equilibrium. Mild episodes may feel more like a rocking sensation or mere light-headedness.

The vestibular system, located in and around the ear, is responsible for integrating what we see, hear and feel with head and body movement. In short, it controls our body's sense of equilibrium. More specifically, the vestibular system works by monitoring head movement and then sending this information to organs inside the ear, which then relay the information to the brain.

Our ears play an essential part in this process. The inner ear contains an area called the labyrinth, in which are found three semicircular canals; these canals are surrounded by a special fluid. The canals' function is to transmit information about head movement to the vestibular nerve. This nerve passes the information along to the areas of the brain that control bodily coordination.

People with BPPV feel lightheaded. The lightheadedness is is often accompanied by nausea, vomiting, sweating and a skin pallor. It usually comes on suddenly and goes away in less than 30 seconds.

BPPV can be brought on by a sudden change in body position, such as turning over in bed or getting in and out of bed. Many people have only a single passing bout of BPPV but, for some, BPPV returns unexpectedly.