JUST the other day, I experienced a sudden bout of dizziness. This dizziness was unusual. I saw everything around me spinning round and round. I had to sit down on the ground. I visited a doctor and he told me I had vertigo. What is it?

Vertigo is not a disease, but a symptom. It is described as a spinning or whirling sensation that is caused by a disturbance in your balance or equilibrium. This is usually as a result of a disorder in your vestibular system.

If you experience a sensation of you yourself spinning, that's called subjective vertigo. If you think the objects around you are spinning instead, that's called objective vertigo.

Vertigo is worsened when you move your head, change your position, or lie down.

I have never heard of a vestibular system before. Where is it?

These actually involve the structures in your inner ear, and the nerve that connects it to its corresponding area in your brain, namely your brainstem and cerebellum.

Your sense of balance or equilibrium is maintained by this vestibular system. It allows you to stand upright, maintain your balance, and move. It coordinates and processes information from your inner ears, eyes, muscles, joints, fingertips, palms, soles, jaw, and gravity receptors on your skin and maintains how you balance yourself.

When your head moves, the signals are transmitted to your inner ear's labyrinth, which contains three semicircular canals surrounded by fluid. The labyrinth then relays the signals to your vestibular nerve, and thereupon to your brainstem and cerebellum, which are the areas of the brain that maintain posture, balance, coordination, and your sense of placement.

Because your vestibular system is so closely connected to your hearing (auditory system), anything that affects your auditory system can also affect your vestibular system.

Is vertigo dangerous then? Is it very common?

Vertigo in itself is dangerous if it makes you fall and injure yourself, such as if you experience it when you are on a balcony with a broken railing and somehow fall over!

The cause of vertigo has to be ascertained, and whether it is dangerous or not will depend on what is actually causing the vertigo, such as a tumour that is impinging on your vestibular system.

Vertigo is so common that four out of 10 people will actually experience it at least once in their lifetimes. It's more common in women than men, and also in older people.

What causes vertigo?

The causes of vertigo can be divided into two areas relating to which part of your vestibular system is affected - peripheral (inner ear) or central (vestibular nerve, brainstem and cerebellum).

In a lot of cases, no cause for your vertigo can be found.

Under peripheral vestibular disorders, the most common causes are:

-Benign Paroxysmal Positional Vertigo (BPPV). This one occurs most often when calcium debris builds up in one of the semicircular canals in your inner ear. It also occurs when your inner ear is affected by infection or injury.

This type of vertigo is usually intermittent and only lasts for a few seconds. It may be exacerbated by a change in your position, such as when you get out of bed or get up from a chair suddenly. Since it affects the inner ear, BPPV may also be accompanied by hearing loss.

-Meniere's disease: this happens when the pressure in your inner ear fluid fluctuates. It is also accompanied by ringing in your ears (tinnitus) and progressive deafness.

-Ear poisoning (also called ototoxicity) by some medications (the aminoglycoside group of antibiotics, certain anti-cancer medications containing platinum, antiepileptics, antidepressants) and chemicals such as lead, mercury and tin. Alcohol can also cause vertigo.

-Infection of the vestibular nerve (vestibular neuritis).

Central vestibular disorders may include anything that can affect that part of your brain, such as stroke, injury, migraine, multiple sclerosis, diseases that affect the entire body (such as kidney disease or thyroid disease), tumors, and so on.

Is vertigo treatable?

Definitely - treat the cause, and you get rid of the vertigo. If vertigo is caused by a drug, for example, you have to stop the drug. If it is caused by an infection, then the doctor will have to treat the infection with antibiotics.

BPPV can be treated with something called canalith repositioning, in which, basically, the patient is guided by the doctor to perform a series of head and body movements designed to reposition the calcium deposits in your ear canal! If this fails, you can take meclizine, an oral anti-vomiting drug.

Meniere's disease can be treated by reducing your salt intake and being prescribed diuretics.

There is also a form of physiotherapy for vertigo, in which you perform a series of exercises to improve your balance. It's called Vestibular Rehabilitation Therapy.