U2 sang about it and Alfred Hitchcock made a movie about it. Talk to anyone and they're guaranteed to tell you they have experienced it at least once, if not often. Science calls it “vertigo,” and it's not really as commonplace as many might think.

Most people who complain of vertigo are probably just dizzy. The latter condition affects 20 to 40 percent of people at some point in their life, while vertigo only engages about 7.5 to 10 percent.

True vertigo is usually caused by an inner ear problem. It's the inner ear that communicates to the brain in matters of gravity and balance. 

The inner ear can be disrupted by tiny calcium particles accumulating in the inner canals (a condition known as “benign paroxysmal positional vertigo”). Vertigo is also a result of Meniere's disease, another inner ear ailment, this time resulting from a buildup of fluid and a change in pressure. Inflammation of certain nerves in the inner ear (a condition called “labyrinthitis”) also results in vertigo.

People afflicted with vertigo typically describe it as feeling like they are:

•    Spinning
•    Tilting
•    Swaying
•    Unbalanced
•    Being pulled to one direction
•    Feeling nauseated
•    Nystagmus, i.e., abnormal or jerking eye movements
•    Headache
•    Sweating
•    Ringing in the ears or hearing loss

These symptoms can last a few minutes to a few hours or more and may come and go.
Your brain is adept at compensating for balance and inner ear problems, so vertigo – itself a symptom of another ailment –  will often go away without any kind of treatment. Diuretics are often used to treat Meniere's disease, while a regimen of antibiotics may be the ticket for removing inner ear inflamation.

For more chronic inner ear problems, your doctor may prescribe vestibular rehabilitation. This is a type of physical therapy aimed at helping strengthen the vestibular system, the function of which is to send signals to the brain about head and body movements relative to gravity.