Frequent flyers collect health anxieties the way they collect boarding passes: jet lag, radiation, blood clots, dodgy cabin air. The Independent's Global Travel Editor Annabel Grossman decided to find out which of these actually deserve attention, so she asked Miles Levy, consultant endocrinologist at University Hospitals of Leicester, for a straight answer.
The good news first: most of the scary stuff isn't worth losing sleep over — literally. Grossman had been warned by another doctor that her rapid-fire trips across multiple time zones (the US, Indonesia and Finland within weeks) might shorten her life by disrupting her circadian rhythm. Levy waved that concern away. Yes, shifting your sleep schedule leaves you feeling rough — the 3am wake-ups, the mid-afternoon slumps — but human bodies are resilient and occasional long-haul travel won't cause lasting harm.
Radiation is another worry that shrinks under scrutiny. A dentist once told Grossman that a single wisdom-tooth X-ray delivers about the same dose as a flight from New York to Los Angeles — an unsettling thought for someone who flies thousands of miles regularly. Levy's verdict: radiation is "not really a risk" and only a minor consideration even for very frequent flyers. For the average holidaymaker taking a few flights a year, it's a non-issue.
One genuine risk does make the list: deep vein thrombosis, or DVT — blood clots that can form in the legs during long periods of sitting. Levy's advice is refreshingly simple. Stay hydrated and drink plenty of water, which itself lowers the risk. On any flight longer than four hours, walk the aisle and do calf exercises. Anyone at high risk of DVT should wear compression stockings and have a word with their GP before flying. That's it — no elaborate routines required.
Cabin air is the last item, and it's more of an inevitability than a preventable hazard. Levy admits he often gets a sore throat after flying, describing the plane as a metal box full of strangers, kids and babies where the ventilation system turns the cabin into "a perfect melting pot for viral infections". He half-jokes that this explains why so many people caught Covid returning from ski trips in March 2020. Grossman's own bout of Covid followed a New York-to-UK flight. Packed cabins do spread bugs — so hand sanitiser and a decent immune system are worth more than any fancy gadget.
The overall takeaway is reassuring for anyone who flies a handful of times a year for holidays or work: several hours on a plane now and then doesn't meaningfully raise your health risks. The disruptions you feel — grogginess, dry skin, a scratchy throat — are temporary and manageable. And, as Grossman points out, the mental boost from exploring new places and cultures comfortably outweighs the downsides.
So the practical checklist is short: hydrate properly, move your legs on flights over four hours, wear compression stockings if you're in a higher-risk group, and accept that you might pick up a cold. Then keep travelling. Even the doctor's orders come with a light touch — the worst long-haul flying does to most of us is make us tired, and that's fixable with a good night's sleep on arrival.
