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Frequent flyer: the effects of air travel on the human body

Is there a human cost to being able to jet off at will? Alas, it’s not exactly the healthiest thing you can do — and it’s worth knowing the toll it takes on the human body.

By David Whitley
Published 11 Mar 2020, 06:00 GMT
Passengers on an airplane.
The main aspect of in-flight health that most of us will encounter is tiredness and changes to circadian rhythms.
Photograph by Getty Images

Flying really isn’t good for you, right?

Of course not. But perhaps the most remarkable thing is how little damage being sealed in a pressurised cabin with hundreds of other people and their germs does to you. Flying does expose you to higher levels of radiation, but not dangerously so. You’ll get more from a chest X-ray, for example, than a transatlantic flight, though this mounts up a little for frequent flyers. But even airline crew aren’t exposed to nearly enough each year for it to tip into the danger zone — where there’s an increased risk of getting cancer.

What about dehydration?

Dry air circulates around cabins, which can have a dehydrating effect. For those who are otherwise fit and well, this doesn’t cause much of a problem — sometimes dry skin, a dry mouth and/or a mild headache. But the dehydrating effects of being at high altitude and low humidity for hours can exacerbate existing illnesses. Going easy on alcoholic or caffeinated drinks can help, and switching contact lenses for spectacles is a wise idea to avoid eye irritation.

And deep vein thrombosis?

It’s a common misconception that deep vein thrombosis (DVT) is something that only happens on flights — it’s more about being immobile than being up in the air. Risks are similar if you’re on a long bus journey, for example. Lack of movement can slow blood flow in the veins, leading to blood clots — usually in the legs — which can potentially break off and cause a life-threating pulmonary embolism. The NHS Fit For Travel site says those who have had recent surgery, are pregnant or obese, or suffer from varicose veins are among the groups at most risk from DVT.

What can be done to prevent it? 

Anti-embolism stockings, if worn correctly, are a good bet, but most of the best preventative measures are behavioural. Advice includes choosing an aisle seat, as this extra room acts as an incentive to move around more, carrying out muscle exercises, avoiding excessive alcohol consumption and staying well hydrated — if only because it’ll make you get up to go to the toilet more often.

Anything else to fret over?

The main aspect of in-flight health that most of us will encounter is tiredness and changes to circadian rhythms. Flying often involves getting up at unsociable hours, inadequate sleep and messing up the body clock — all of which leave us more susceptible to being hit nastily by any bugs that may be floating about. Jet lag, alas, is something there’s no easy cure for. However, there are a number of things that can be done to minimise it. They include — get whatever sleep you can on the plane, try to adjust meal times to the destination, don’t plan much for the first day or take a stopover. And — this should be something of a mantra — try to avoid going the whole hog on the free wine and spirits.

Published in the April 2020 issue of National Geographic Traveller (UK)

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