Flying and Health: What to Do, in Order
Flying and Health: what is worth doing, what is worth avoiding, and when to stop and see a doctor.
The health considerations of air travel, including clots, pressure and infection. Long-haul immobility raises clot risk measurably, and several conditions need clearance or planning before flying.
Key takeaways
- Clot risk: rises with journeys over about 4 hours
- Prevention: move regularly, stay hydrated, consider compression stockings
- Most useful single change: Walk the aisle and exercise your calves hourly on long flights.
- Commonest mistake: Sitting immobile for the whole flight.
- See a doctor if any of the signs under "When to speak to a doctor" below apply to you.
Do
- Walk the aisle and exercise your calves hourly on long flights
- Drink water and limit alcohol
- Carry all essential medicines in hand luggage
- Check with your clinician before flying after surgery or with lung disease
Do not
- Sitting immobile for the whole flight
- Alcohol and sleeping tablets on long-haul flights
- Packing essential medicines in hold luggage
The numbers behind the list
Where the items above come from.
| Measure | Figure |
|---|---|
| Clot risk | rises with journeys over about 4 hours |
| Prevention | move regularly, stay hydrated, consider compression stockings |
| Cabin pressure | equivalent to altitude; relevant in lung and heart disease |
| After surgery | flying restrictions vary; check with your surgeon |
| Medicines | carry in hand luggage with a letter for controlled drugs |
If you change one thing
Walk the aisle and exercise your calves hourly on long flights. It heads the list. If you take nothing else from this page, take that.
Where to go next
- Flying and Health for Beginners: Where to Start
- Flying and Health: The Questions People Actually Ask
- Flying and Health — the reference entry
- Sun and Heat Abroad: What the Evidence Actually Says
- What the Guidance Really Says About Travelling with Medicines
When to speak to a doctor
Call 999 or seek immediate care for sudden breathlessness, chest pain worse on breathing in, coughing up blood, or collapse during or after a flight — this can indicate a pulmonary embolism. Seek same-day assessment for pain, swelling, warmth or redness in one calf after travel.
Where this comes from
- NHS — Travel health: DVT
- Civil Aviation Authority — fitness to fly
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarised or generalised beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to a GP, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 999.
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