Staying Healthy on a Long Flight

A long flight is a health event mainly because of one thing: you sit still for a very long time. The CDC is direct about the mechanism, noting that travel often involves sitting for periods of time, which can increase your chances of developing a deep vein thrombosis. Everything else, the dry air, the pressure, the timing of meals, is real but secondary. The advice that follows from this is unglamorous and it works.

What You Need to Know

Blood clots

A deep vein thrombosis is a clot that forms in a large vein, typically in the leg. It matters because part of it can break off and travel to the lungs, blocking an artery there, which is a pulmonary embolism. The CDC describes these clots as rare but very serious, which is the right way to hold both halves of the fact: not a reason to fear flying, and a reason to take the simple precautions.

Those precautions are movement and position. The CDC’s specific advice is to select an aisle seat where possible so that you can walk around every two to three hours. If you cannot get up, flexing your calves, rotating your ankles and shifting position in the seat all help. Loose clothing helps; crossing your legs for hours does not.

Who should ask a doctor first

Risk is not evenly distributed. Recent surgery, a previous clot, pregnancy, some cancers, hormone therapy, obesity and limited mobility all raise it. If any of those apply, ask your doctor before a long flight what you should do, which may include compression stockings or, occasionally, medication. That conversation belongs before departure, alongside the four to six week appointment for anything vaccine-related.

The cabin itself

Cabin air is dry and the cabin is pressurized to an altitude noticeably above sea level. Neither is dangerous for a healthy traveler, and both explain the ordinary experience of a long flight: a dry throat, mild puffiness, a headache, more effect from alcohol than usual. Drinking water steadily addresses most of it. Alcohol and caffeine do not help, though a single drink is not the problem people sometimes make of it.

What to Do Before Your Trip

• Book an aisle seat on a long sector if you can, for the reason the CDC gives.
• Speak to your doctor if you have any of the higher-risk factors above.
• Put medication in the carry-on, in labeled containers.
• Pack an empty bottle to fill after security, so drinking steadily is easy.
• Wear clothing you can move in, and shoes you can get back on.

Important Considerations

Two structural facts about long-haul flying make the advice easier to follow. First, movement opportunities cluster: the hour after the meal service is when the aisles are clearest. Second, a connection is a movement opportunity, and a traveler with a four-hour layover who walks it is better off than one who sits at the gate.

Sleep on the aircraft is worth having but not worth forcing. If you are crossing enough time zones for it to matter, the useful question is what time it is where you are going, which is the subject of Hydration and Jet Lag. Sleeping medication on an aircraft is a decision for your doctor, and it interacts badly with the sitting-still problem if it stops you moving for eight hours.

If you are unwell before departure, particularly with anything respiratory or with an ear or sinus problem, the pressure change can be genuinely painful and airlines can and do decline carriage. Ask a doctor rather than hoping.

Tips for Group Travelers

• Ask about mobility and clot history privately when you collect health information.
• Get aisle seats for the travelers who most need to move, not by seniority.
• Prompt the group to walk once or twice during a long sector. Most will not otherwise.
• Use a long layover as a walk, deliberately, rather than as gate seating.
• Do not schedule anything demanding on the arrival day.

Common Mistakes to Avoid

• Sitting for the entire flight because the window seat makes moving awkward.
• Treating a clot risk factor as not worth mentioning to a doctor.
• Sleeping medication that prevents you moving for many hours.
• Waiting to be thirsty rather than drinking steadily.
• Packing essential medication in the hold.

Frequently Asked Questions

How often should I get up on a long flight?

The CDC advises walking around every two to three hours, and suggests choosing an aisle seat so that you can. If getting up is difficult, moving your legs in the seat, flexing your calves and rotating your ankles are worthwhile substitutes.

Are blood clots on flights common?

The CDC describes them as rare, and also as very serious, because part of a clot can break off and travel to the lungs. Both halves matter: the risk is low for most travelers, and the precautions are simple enough that there is no reason to skip them.

Do compression stockings help?

They are commonly recommended for travelers at higher risk, and whether they are right for you is a question for your doctor rather than for a guide. If you have had a clot, recent surgery, or another risk factor, raise it at the same appointment where you discuss the trip.

How much water should I drink?

Enough to avoid feeling thirsty, taken steadily rather than in one go. Cabin air is dry and there is no target number that fits every traveler and every flight length. Carrying a bottle filled after security makes it far more likely to happen than relying on the drinks service.

Related Travel Tips

• Health, insurance and travel protection, the section this guide belongs to.
• Hydration and Jet Lag. What happens after you land.
• Long-Haul Flight Tips. The practical side of the same flight.
• Traveling With Prescription Medication. Dosing across time zones.

Plan Your Trip With LABUSA Travel

Which routing involves ten hours in a seat and which breaks it into two manageable sectors is a real choice, and it matters more for some travelers than for others. LABUSA Travel builds the itinerary around who is actually going.

Talk with a LABUSA Travel advisor about a trip you are considering, or browse our destination guides for a specific country.

Verify Before You Travel

Guidance on blood clots during travel is published by CDC Travelers’ Health. This page is general guidance and not medical advice; whether any precaution is right for you is a question for your own doctor, particularly if you have a history of clots or recent surgery.