Have you ever wondered why some of us get motion sickness, while for others it's plain sailing? And why do babies find air travel so distressing? Dr. Lesley Hickin explains

Ear problems
These are very common in air travel and can result in temporary pain and hearing loss.

Why it happens: the middle ear normally contains air at atmospheric pressure. Usually when you swallow, the Eustachian tube opens and air enters your middle ear from your mouth. If the tube is blocked for any reason the air pressure in the middle ear drops, pulling the eardrum towards it and causing pain. If it remains blocked the middle ear can fill up with mucus, produced by the lining membrane.

When you travel by air your middle ear is exposed to rapid changes in pressure and so you must swallow frequently to equalise the middle ear pressure with that of the surrounding air. If your Eustachian tubes are blocked this does not happen so you can develop severe earache and sometimes the eardrum bursts.

How to unblock ears

• Swallowing: suck a sweet or chew gum; feed your baby or give him a dummy to suck.
• Yawning: works even better.
• Stay awake during taking off and landing.
• The Valsalva manoeuvre: if the above do not work try this manoeuvre:
  1. Hold your nostrils closed.
  2. Breathe in and close your mouth.
  3. Force air backwards into the back of your nose using your cheek and throat muscles. If this is successful you will hear a pop and feel the pressure change in your middle ear. Repeat as necessary.

Travel sickness
This is a very unpleasant problem that can ruin your holiday. It is also known as motion sickness, seasickness and mal de mer.

It is particularly commonly found in childhood and tends to become less of a nuisance as you get older. However, in severe sea swells whole shiploads of people can be affected. Research has found that women are more susceptible to the symptoms of motion sickness than men, particularly the nausea. In fact, women report symptoms of nausea up to four times as frequently as men, whatever the cause.

Why it happens: the symptoms are brought on by the brain receiving conflicting messages from the sensory input of the eyes, balance organs and body spatial receptors. For example, if you are travelling by car and reading at the same time, your eyes send the message to the brain that you are stationary, while your inner ear tells the brain that you are moving. This sets off a chain of self-perpetuating reactions in the unconscious part of the brain.

Even astronauts get travel sick. Research has reported that a large number of US space shuttle astronauts suffered from motion sickness, particularly in the first two or three days of their mission. This is due to the repetition of sudden head movements.

Emotional factors and anxiety are also involved. A lot of research has gone into testing ginger root and sensory deprivation to overcome the problem, but the best results were from biofeedback techniques (teaching your body to react in different ways).

The symptoms: at their mildest, symptoms include a feeling of discomfort and uneasiness. As things get worse you feel sick then develop headache, dizziness and tiredness. If the motion continues you can get worse, with sweating, pallor, yawning and hyperventilation occurring. Vomiting can be severe and prolonged.

How to beat travel sickness
Various drugs are available for travel sickness but they all need to be taken before the journey. Some are available over-the-counter and others need a prescription. Some may cause drowsiness and you should note the risk of driving after taking these drugs.Some also interact with alcohol and other medication.

• Hyoscine (Kwells, Junior Kwells) is the most effective of these drugs and is available over-the-counter in tablet form, plus soluble tablets for children. It is also available in patch form that you can stick on to your skin prior to travelling and its effect lasts up to 72 hours. It should not be taken if you suffer from glaucoma, and can occasionally cause drowsiness, visual disturbance and a dry mouth.
• Antihistamine drugs (Stugeron, Sea-Legs) are also sold for travel sickness.
• If you are wary of the side effects from medication or you only have a mild problem, you could try an elastic acupressure wristband. This is worn on each wrist like a watch or sweatband and applies constant pressure to the P6 meridian point on each wrist. The manufacturers claim it is effective in preventing the symptoms of travel sickness, although no controlled trials have been reported.
• There is some evidence that foods such as ginger have a beneficial effect on motion sickness, though this is more likely to be from an effect on the gastro-intestinal tract than the balance mechanism.
• Choose the right seat: always travel where your eyes will see the same motion that your inner ears and body will experience. For example, go on deck when travelling by boat. Choose a seat in an aeroplane over the wings, where the motion is less, and by a window so you can see the direction of travel. Sit in the front of the car and do not read - even map-reading can precipitate an attack. If you are going on a cruise and are prone to seasickness choose your season of travel and geographical location with care. Bigger is definitely better when it comes to ships. Do not lie in your cabin but find a chair on deck in the fresh air.
• If you are suffering from an attack of motion sickness, try to have a break in your journey for a while to let your system adjust.
• Only eat light meals, avoiding spicy or fatty food.