The stress air travellers encounter is dissimilar to any other experienced in surface forms of transport. It is the flight itself, which presents numerous physiological challengers unique to aviation. These include oxygen deficiency, dehydration, gas expansion, time zone changes, and prolonged sitting in a cramped position. There is also the ready availability of alcohol (which increases oxygen lack and the likelihood of jetlag) and the anxiety some passengers feel about air travel.

Irrespective of whether it is caused by anxiety or aggression, stress increases the total concentration in the bloodstream of the stress hormones adrenaline and noradrenaline. The noradrenaline level is raised more by anxiety-stress, such as when we are anxious about flying or about what awaits as at our destination; the adrenaline level is elevated more by aggressive circumstances such as when we have to cope with the crowds or traffic.

Conditions which are distinguished by novelty, anticipation, unpredictability and change produce a rise in adrenaline too. The adrenaline level will fall, however, if we gain control over the situation.

The best method of reducing stress in the flight environment is to gain a measure of control over your situation. This will immediately result in a decrease in the secretion of stress hormones. There are two main sources of stress: the airport and the aircraft.

The first step in reducing stress on the ground is to allow yourself sufficient time to check it, at least an hour before a domestic or short-haul flight, and some two hours before an international flight (recent security considerations may make it advisable to allow even more time). Remember that airports are crowded places with queues, long distances to walk, immigration controls, security checks and the inevitable flight delay. Once you have allocated an appropriate amount of time for departure, you can fill the interval to your best advantage by following these tips-

• Ensure that you exercise, to consume the energy that has accumulated through the stress hormone secretions. Brisk walking along the concourse will suffice.
• Relax your mind, either by reading an interested book or dealing with a backlog of work.
• Reduce the weight of your hand baggage by checking in more for the cargo hold and keeping only essential items.
• Elderly or overweight passengers, or those with serious heart conditions, should ensure that ground transport is available. Notify airline staff on arrival.
• Communicate with other passengers if you find that you are edgy or tense. This can help diffuse your feelings.

On board, there are various ways to keep stress at bay-

• Distract yourself with interesting or light reading material, the film, music channels, conversation or by focusing on activities planned at your destination.
• When flight attendants bring round hot towels, one option is to place it at the nape of your neck to release tension.
• Avoid eating chocolates, soft cheeses, citrus fruits or yeast extract and do not drink red wine - each of these can cause hypertension because they introduce tyramines into your system, which prevent glucose in the blood from being synthesised.