Giddiness, dizziness, feeling light-headed or faint, seeing the room swim — all these are symptoms that most people have felt at some time. Usually, such symptoms disappear after a few minutes.

The brain receives inputs from the eye, ear and peripheral muscles. These signals are processed and synchronised in the brain. Efficient synchronisation prevents giddiness and maintains balance. Sometimes the signals conflict. As a result, the brain cannot make assumptions about the body’s orientation, movement and position. The most typical time of such disturbance is while travelling. The body is stationery (muscle signals), but the eyes sense rapid movement. If there are twists and turns on the road, the ear’s vestibular (balance) apparatus also gets disturbed.

Motion sickness is one of the commonest causes of vertigo. Sitting facing forward helps. Otherwise, antihistamines such as dimenhydrinate (Dramamine) or diphenhydramine (Benadryl) taken at least an hour before travel can prevent the symptoms.

Benign paroxysmal positional vertigo (BPPV) occurs in older people, especially women. It may be due to tiny particles called otoliths in the ear becoming loose and floating around. They irritate the tiny hairs that line the middle ear and are responsible for the signals for balance.

Often, staying still, lying down, moving very slowly, applying equal pressure to both temples simultaneously with the palms and drinking plenty of fluids makes the symptoms subside in an hour or two.

To correct BPPV, ENT surgeons or physiotherapists do the Epley manoeuvre. You can also do it at home. Sit on the edge of a bed and turn the head 45 degrees in the direction of the problem ear. Place a pillow underneath the shoulder and lie down with your face pointing upward. Wait 30 seconds, turn the head 90 degrees in the other direction, and wait another 30 seconds. Relief is usually immediate but it may be temporary. As a result, the manoeuvre may have to be repeated several times.

Dehydration, hypoglycaemia, anaemia as well as viral and bacterial infections of the ear or the eigth cranial nerve (vestibular neuronitis) can also cause giddiness. It can also occur if the bones of the neck are not in perfect alignment. Nerves can get pinched and blood supply to the brain compromised. Some medications, especially anti-epileptics or antidepressants, can cause giddiness. If hypertension is aggressively controlled, it can sometimes result in low blood pressure and giddiness.

Giddiness that persists for three days or more requires evaluation of blood pressure, sugars, lipid profile and tests such as X-ray of the neck and CT scan or MRI of the brain. However, very often, no discernible cause can be found.

If the giddy feeling is accompanied by weakness in one side of the body, headache, confusion, slurred speech, irregular heartbeat, vomitting, seizures or severe headache, consult a physician immediately.

There are certain things to keep in mind until a diagnosis is made. Losing balance can result in fractures. Get up slowly, and use a cane if needed. Do not suddenly change direction. Keep the room well lit. As soon as you feel dizzy, lie down and press both temples firmly. Do not drive and cut down caffeine intake.

There are also lifestyle changes you should make. Reduce salt intake to half teaspoon per day and drink plenty of fluids. Do not drink or smoke. Do a combination of neck exercises (physiotherapy) and yoga regularly.

The writer has a family practice at Vellore and is the author of the book Staying Healthy in Modern India. If you have any questions on health issues, please write to yourhealthgm@yahoo.co.in