6 ways flying can affect the body

Shozab Khan Shozab Khan General Practitioner
Flying is one of the most trusted methods of transport in the world today. Many of us silently dread the ascent to 30,000 feet and there are some minor and potentially severe ailments and conditions that can develop when we get there.

Keep reading to learn what happens to our body when we fly and how some small adjustments to your pre-flight routine can help make the entire experience a healthier and happier one.

1. Nervousness and anxiety

Although statistics show that flying is one of the safest forms of transport (and it’s only getting safer), this doesn’t stop many of us feeling nervous, anxious, or even distressed in the run-up to our summer holiday.

It’s important to break this down and determine the extent and nature of your anxiety. Airports are busy stressful places, and traveling requires many moving parts to line up for us to get to our destination.

It’s therefore important to determine whether you’re experiencing ‘normal’ levels of anxiety that include things like remembering your passport, landing in a foreign country, and having the right clothes and currency, or if you’re experiencing something deeper that may require more than just a positive attitude.


Aerophobia is an extreme fear of flying in an airplane. People with this phobia aren’t typically afraid of the plane crashing. Instead, the fear is around actually being on the plane. The anticipation of flying, thinking about flying, and many related tasks are often as troublesome as being on the plane itself.

Whereas stress and anxiety around trips can be alleviated with better planning, getting additional information, and building in more predictability and preparedness into the process, Aerophobia, also called Aviophobia, needs to be treated by a professional.

Treating a fear of flying can involve cognitive behavioural therapy (CBT) to address and reframe some of the negative thoughts and anxieties we associate with air travel. Practising relaxation techniques such as deep breathing and mindfulness can also help calm the physical symptoms.

Ultimately, gradual exposure to flying (either through virtual simulations or short, incremental flights) can desensitise us to the fear we’ve built up around flying and build confidence in the safety of air travel. Courses like the EasyJet ‘Fearless Flyer’ course help people who are nervous about flying address their anxieties in a safe and controlled environment.

2. Deep vein thrombosis

A well-known condition that can occur as a result of flying is blood clot formation in one of our deep veins. This is officially known as deep vein thrombosis (DVT) and is most common in the legs. A number of factors in aircraft cabins have been reported to increase our risk of developing DVT, including:

  • Cramped seating positions
  • Immobility
  • Dehydration and the consumption of alcoholic and diuretic drinks like tea and coffee
  • The low humidity of the aircraft cabin
  • Lower oxygen at such a high altitude
  • Cabin pressure.

Deep vein thrombosis can be serious because blood clots in the veins can break loose. The clots can then travel through the bloodstream and get stuck in the lungs, blocking blood flow (this is called a pulmonary embolism). It’s important to remember that this is a life-threatening condition.

We can take measures to prevent the formation of DVT and measures to stay vigilant after our trip, as it can take months for the clots to dissolve.

To prevent DVT when flying, try the following:

  • Stand up or walk occasionally.
  • Select an aisle seat when possible so you can walk around every 2-3 hours
  • Exercise your calf muscles and stretch your legs while you're sitting
  • Raise and lower your heels while keeping your toes on the floor
  • Raise and lower your toes while keeping your heels on the floor
  • Tighten and release your leg muscles
  • Talk to your doctor about wearing compression stockings
  • Talk to your doctor about taking medicine before departure if you have additional risk.

If you have recently flown and believe you’re at risk of developing a DVT, you should look for symptoms for at least a month after flying:

  • Swelling in the leg or arm
  • Pain or tenderness in either area
  • Painful or swollen areas hurt and are warmer than usual
  • Discoloured skin
  • Veins that are more pronounced or visible than usual
  • Abdominal pain
  • Severe headaches

Finally, if you have any prior conditions that pre-dispose you to DVT or any other risk factors like a recent pregnancy, obesity, or you’ve recently undergone chemotherapy treatment, we recommend consulting your GP before you fly.

3. Jet lag

To understand jet lag, we first have to understand the body’s circadian rhythm. Circadian rhythms are the physical, mental, and behavioural changes that we experience over a 24-hour cycle. Light and dark have the biggest influence on our circadian rhythm, but food intake, stress, physical activity, social environment, and temperature also affect them.

Most living things have a circadian rhythm, including animals, plants, and microorganisms. With regard to jetlag, it refers to a set of symptoms (usually sleep-related) that can occur when we fly into a new time zone. Our mind and body naturally use the sun to structure our day, which means we intuitively know when to wake up and go to sleep. When we enter a new time zone, this changes, which can throw our body out of sync.

When we cross time zones too rapidly, a “misalignment” of our circadian rhythm occurs. The change in light exposure causes adjusted production of melatonin (the sleep hormone), and so when we land after a long flight, we can end up feeling a little dazed and confused.

Other symptoms include:

  • Difficulty concentrating
  • Irritability
  • Stomach problems
  • Lapsed memory
  • Impaired judgement
  • Insomnia
  • Waking fatigue

To help you avoid jetlag, stay hydrated, limit your light exposure in the run-up to your flight, and try your best to sleep on the plane if you’re landing in the morning in your new time zone.

4. Picking up a cold

Low humidity and proximity to other passengers make the cabin on an airplane the perfect transmission ground for the common cold. If you regularly return from your summer holiday with the sniffles, chances are it’s not all bad luck. Research suggests you may be as much as 100 times more likely to catch a cold on a plane than you would elsewhere.

We’ve put together a list of four things you can do to help minimise your risk below:

  • Wash your hands: the sheer amount of people on a commercial aeroplane means lots of hands touching lots of things. Wash and sanitise yours regularly and avoid touching your face where possible to prevent cross-contamination
  • Stay hydrated: staying hydrated is a great way to fend off the common cold. When we’re dehydrated, our immune system is compromised, leaving us more susceptible to picking up cold and flu
  • Wear a face mask: while not mandatory on most airlines anymore, wearing a mask became second nature for frequent flyers during the COVID-19 pandemic. Wearing a mask is still common today, with many people wearing one to guard against the spread of colds and flu
  • Eat well before you fly: stay away from greasy, processed foods that are filled with salt as they can be dehydrating. Eat something light before you fly and pack some healthy snacks to eat onboard.
  • Take Supplements: using immunity boosting supplements available at health food shops are known to have a protective effect and support your body in fighting off potential infections
  • Get enough rest: when on holiday, we try to make the most of our time away and pack in as much as possible. However, exhaustion and a lack of sleep will lower your body’s defences, making you more vulnerable to flu-like illnesses and infections.

5. Dehydration

Air travel involves a unique set of environmental conditions that can contribute to dehydration. The cabin of an airplane is both pressurized and characterised by low humidity, which are two factors that can lead to fluid loss and dehydration.

Factor in readily available alcoholic drinks and salty food, and you have a recipe for dehydration.

Maintaining adequate hydration levels while flying can significantly reduce the chances of experiencing dehydration after a flight. It's a multifaceted process that starts before you even board the plane and continues throughout your journey.

  • Before:  consuming an adequate amount of water in the hours leading up to your flight can help ensure your body starts the journey well-hydrated
  • During: a common recommendation is to consume at least one cup (about 250 ml) of water for every hour in the air. However, this can vary based on individual needs, flight duration, and cabin conditions.

6. Motion sickness

Motion sickness in flight (otherwise known as airsickness) is a real problem for many people. The most common symptoms of this condition are nausea, stomach pain, vomiting and dizziness.

The condition is caused by the plane moving and oscillating whilst it is in flight. To ease your symptoms, here are some suggestions:

  • Eat a light meal before boarding the plane: flying on an empty stomach, contrary to popular belief, does not help to avoid airsickness
  • Choose the right seat for you: pick a seat close to the window and try to focus on a point on the horizon to give your brain an external reference. If you are travelling after sunset, choose a seat in the middle of the plane, where the movements and oscillations of the aircraft are less dramatic
  • Avoid reading or staring at the screen of an electronic device for a long time: just as with carsickness, concentrating on an object in your hands or inside the cabin contributes to a loss of orientation, causing nausea. Try to look out of the window and only concentrate on details in the cabin for short periods
  • Chew some minty chewing: mint flavouring also has a soothing effect on the stomach, alleviating the sensation of nausea and indigestion
  • Use anti-nausea drugs or natural remedies: there are various options commonly available, from over-the-counter drugs for airsickness to prescribed sedatives and antihistamines. There are also some very effective natural remedies for airsickness, such as ginger, or lemon. If you tend to vomit, then it is a good idea to get your GP to prescribe some anti-emetics for your journey.

Last updated Monday 24 June 2024

First published on Monday 24 June 2024