Does Flying Dehydrate You? Your Guide to Air Travel Hydration

by Sarah Peterson

does flying dehydrate you

When you fly, you likely experience some of the more visible side effects of dehydration. 

Dry, flaky skin, chapped lips, peeling cuticles, and even nosebleeds are common after spending even a short period of time in the air. 

So are headaches, sluggishness, digestive issues (gas, constipation, and bloating anyone?), swelling, and just generally feeling… depleted. 

So what gives? Does flying dehydrate you? Or should these travel health symptoms be blamed on one of the myriad other stressors your body undergoes at 30,000 feet in the air?

The answer: Yes, flying does leave you more susceptible to dehydration

This article will explain why that is, the symptoms of travel dehydration, and how to avoid those in the future. 

Article Guide

Why Does Flying Dehydrate You So?

While technology and human ingenuity have unlocked our ability to travel across the world in record-time, hurdling through the air above Earth’s protective ozone layers is not exactly natural for the human body. 

So, when you fly, your body experiences several challenges as a result of being in such an unusual environment. One of those challenges is maintaining proper hydration levels. 

There are a handful of reasons for travel dehydration, and understanding why this problem happens is the first step in remedying it. 

    • Water loss. Apparently, research shows that the conditions of an airplane can lead to 1.5-2 litres of water loss in a 10-hour flight[*] despite water intake. 
    • Lower air pressure. While the aircraft cabin is highly controlled, it’s still subject to shifts in altitude. Aircraft tend to have low air pressure, which contributes to dehydration by necessitating increased respiration - ie breathing. 
    • Extremely low humidity levels. Cabin air is dryer than the Sahara Desert. Seriously. You can expect a typical passenger aircraft to have about 12% humidity. The Sahara sees about 25% humidity. It has to be this way; to support a more comfortable humidity level, the aircraft would have to carry gallons of heavy, expensive water, and would be at risk for excess condensation which can be damaging and corrosive to the parts of the aircraft. 
    • Decreased fluid intake. Most people don’t even drink enough water when they’re at home, let alone on travel days, and decreased fluid intake doesn’t just come from the (lack of) water you’re drinking. The reduction of H20-rich foods like fruits, vegetables, and whole grains can contribute to dehydration as well because 20% of your daily fluid intake tends to come from food. A lack of accessible, convenient, and portable food is a common traveler pain point. 

If these drivers of travel dehydration don’t seem like a big deal, consider this: 

Around 60% of your body is made up of water. Water is required for the proper functioning of virtually every bodily system. 

Mild dehydration can happen when you lose just 1.5% of the water in your body. The average 70kg human body has around 43 liters of water at normal levels. 

This means that if you were to lose the 2 liters of H20 from water loss alone when you fly, you’d be saying goodbye to almost 5% of your fluid volume.

That’s more than 3x the amount of water loss that qualifies for mild dehydration. And that’s not even counting the other sources of airplane dehydration! 

It’s no wonder you feel so dehydrated when you fly. And when you do, you’re likely to experience a host of side effects. 

Symptoms of Dehydration After Flying

Even mild dehydration can cause you to feel groggy, grumpy, and unwell. 

And because there are so many contributing factors to dehydration when you fly, you may experience the symptoms of dehydration after flying even more noticeably. 

Here are some of the more common side effects. 

Lethargy and Fatigue 

Nope, it’s not just your circadian rhythm responding to being transported across timezones; you’re so tired when you travel for many reasons, not the least of which is dehydration.

One of the first symptoms of dehydration is often fatigue, which explains one of the reasons you may feel exhausted after a day of travel even if you didn’t land in a different time zone. 

In fact, studies have shown that those who are dehydrated can experience not only fatigue, but also mood swings, brain fog, reduced cognitive abilities, and confusion[*]. 

Difficulty Overcoming Jet Lag

Nearly all bodily processes require fluids to function properly, and your internal clock, or circadian rhythm, is no exception. 

Your body needs plenty of water to regulate your circadian rhythm, which is especially important when you’re traveling across time zones. 

The circadian rhythm relies on hormonal responses, which can be dysregulated by dehydration and electrolyte imbalance (which go hand-in-hand). 

Both dehydration and electrolyte imbalance can contribute to insomnia and difficulty sleeping, as well, which aggravates your circadian system and makes jet lag even harder to recover from. 

Read More: How to Beat Jet Lag: 15 Simple Strategies & Tips

Gas, Bloating and Digestive Upset

Water plays a crucial role in virtually every digestive process. 

When you’re dehydrated, you’re at risk of constipation and slowed digestion which results in gas, stomach pain, and bloating (a very common problem also known as “jet belly” in the travel context!)

Compromised hydration is not the sole culprit for digestive problems when you travel, but it certainly contributes. 

A Suppressed Immune Response

Water has a big, important role to play in the majority of your bodily functions, including your immune system response. 

Having dehydrated mucous membranes (especially in the nose) leaves us more vulnerable to airborne viruses by compromising their ability to filter bacteria and viruses. 

As we saw above, dehydration can also cause slowed circulation, digestive issues, and fatigue, all of which impair the immune system.

Brain Fog & Reduced Cognitive Function 

All of you business travellers listen up: air travel is hard enough on your energy levels and ability to think clearly as it is. 

High altitudes and recycled air reduce the levels of oxygen to your brain, causing confusion and that feeling of being not-so-sharp. 

Dehydration from air travel can aggravate this issue. Meaning that when you land, you may not be as quick on your feet as you need to be.

A Multitude of Skin Problems

If you’ve ever caught a glimpse of yourself in the airplane lavatory mirror and wondered just how you managed to age so quickly, you can find comfort in this: 

Travel takes a toll on your skin, and while the dry, flaking skin on your face may be uncomfortable, it’s unlikely to be long-lasting. 

That said, dehydration aggravates skin issues, and not getting enough water when you travel may contribute to: 

  • Dry, flaking skin 
  • Eczema flareups 
  • Cracked, itchy hands or heels 
  • Peeling cuticles
  • Brittle nails 
  • Tender, dry inner nose 
  • Dandruff
  • Breakouts and acne.

Sore, Bloodshot Eyes

When you notice that you have bloodshot eyes after your flight, this is a side effect of having dry eyes. 

Dry eyes can be caused by many factors when you fly, including cabin air quality, sleep disruption, compromised tear production in the eye, and, of course, dehydration. 

Eyes more scratchy than bloodshot? Dehydration may be to blame for that, too. 

Swelling and Circulatory Issues

Among keeping other crucial bodily processes running smoothly, water is vital to keeping your blood circulation from slowing, which can cause swelling. 

The extended period of time in a seated position force the fluids in your body to your extremities (and thus deprives said fluids from benefiting your other bodily functions). 

Gravity draws fluid to your lower leg and feet, which increases your risk of deep vein thrombosis[*].

So if your fingers and feet tend to swell when you fly, the culprit may be partially dehydration. 

Read More:Swelling When Traveling? Here’s Why It Happens + What to Do

Can You Bring Water on a Plane?

Considering the role that insufficient hydration plays in your overall wellbeing when you travel, you might be wondering: can you bring water on a plane?

Good news for all of those frequent flyers out there: the answer is yes. You can bring H20 on any commercial flight so you can stay hydrated and support your body when it needs it the most. 

If you’ve heard that liquids are controlled, don’t worry. The liquids rule is only for going through airport security. 

It’s true that you can only bring a small amount of liquid through the TSA checkpoint. 

But once you’re on the other side of security, you can beeline straight for a hydration station to fill up your Travel Water Bottle so you can avoid falling victim to the symptoms of travel dehydration.

How to Avoid the Airplane Dehydration Problem

does flying dehydrate you

The symptoms of dehydration aren’t pretty in any normal circumstance. 

When you fly, your body undergoes several other challenges that it has to contend with, and not drinking enough fluids not only adds to that list, but it also can worsen the other symptoms of air travel. 

So take a page from these seven strategies to ensure you’re flying high-drated.

#1. Drink More Water Than You Think You Need

Yes, we know it’s annoying to have to use the plane lavatory. Nudging your seatmate awake, squeezing past beverage carts and other passengers, waiting in long, cramped lineups… 

And that’s not to speak of the experience of actually having to use one of the bathrooms. 

But the short-term pain is worth the long-term gain. 

Since dehydration is such a prevalent travel side-effect that leads to so many other impaired bodily processes and symptoms, it’s crucial to stay hydrated and drink plenty of water before, during, and after your flight. 

This is why we developed Flight Elixir as a drink mix. We could have made it in any other form, but we wanted to encourage travelers to stay hydrated through a drinkable multivitamin. 

Aim to drink the equivalent of one 8-oz glass of water for each inflight hour. A 32oz travel water bottle will cover you for a standard 4-hour flight. If you’re struggling to remember to drink up, we’re here to help! 

does flying dehydrate you

We developed The Travel Water Bottle by FLIGHTFŪD to help you stay hydrated on the fly (ie when it’s most difficult to do so!) with motivational time markers.

Once at your destination, keep a water bottle on hand so you can stay hydrated and can track how much water you’re drinking.

You may be able to drink less if you ensure you are consuming enough electrolytes, but it’s best to commit to 8 ounces an hour regardless. 

#2. Increase Your Electrolyte Intake 

Electrolytes are essential minerals that play a vital role in the functions of your body. Electrolyte minerals include sodium, potassium, chloride, magnesium, and calcium. 

Under normal circumstances, your body becomes at risk for depleted electrolyte levels when you’re sick, as it loses these minerals through vomiting, diarrhea, and excessive sweating. 

When you travel, however, electrolytes can be lost through an insufficient water intake as well as poor nutrition, and the result is not good. 

An electrolyte imbalance is one of the reasons many passengers get muscle cramps when they fly. 

It’s also to blame for many sleep issues such as insomnia, as well as irritability, sluggishness, headaches, nausea, fatigue, muscle soreness or spasms, feeling weak, and more serious concerns. 

You can get electrolytes through food, such as bananas and avocados (potassium), seeds and nuts (magnesium), cruciferous vegetables and dairy products (calcium) as well as salty foods (chloride). This is why you feel so much better after eating salty junk food like french fries when you’re hungover! 

However, most find it easier to take an electrolyte-rich supplement when they’re traveling. Sports drinks like Gatorade can do the trick in a pinch, but they’re full of sugar and empty calories, so consider opting for a natural, whole-foods supplement. 

We added coconut water crystals to Flight Elixir to help replenish electrolytes. Coconut water is rich in key electrolytes (specifically potassium, sodium, magnesium, and calcium). It’s particularly rich in potassium.

#3. Hit Pause on Your Low-Carb Diet 

Carbohydrates are an essential nutrient, despite what many low-carb and ketogenic diet enthusiasts would have you believe. 

They’re the primary macronutrient in fruits, vegetables, and grains, and they help your body store and utilize fluids. Carbs put the hydrate in “carbohydrates”! 

Not only does this essential macronutrient help the body to store water, but consuming them can also contribute to your hydration.

Whole carbohydrates and starches soak up the liquid they are cooked in, which you then ingest. So whole-grain, unprocessed carbohydrates such as oatmeal, rice and pasta should make their way back into your diet on travel days. 

Don’t worry. If you’re sensitive to carbs, you can cut back again as soon as you’re on the ground.

#4. Avoid Diuretics (Such as Caffeine and Alcohol) 

This is certainly not the most realistic method for avoiding travel dehydration on this list, but it’s an unfortunate fact of life: caffeine and alcohol are diuretics, which is why you have to pee much more often when you’ve been consuming either. 

A diuretic is a substance that causes fluid loss through increased frequency and volume of urination. 

Rather than your body effectively utilizing the fluids you’re consuming, diuretics cause those fluids to run right through you… straight to your bladder, where you pee them out instead of sending them to your cells and organs. 

This is the main reason you might experience a headache when you indulge on that extra glass of wine. In response, your body may also react by retaining fluids. 

So while we’re not saying you have to skip the wine, consume your spirits wisely inflight (and in general). Drink in moderation, and drink an extra glass of water for each alcoholic drink you consume. 

It doesn’t hurt to ensure you’re drinking your Flight Elixir as well; with coconut water crystals for electrolytes and vitamins to support your body while you travel, we’ve stacked it with the ingredients you need to help you balance your body.

#5. Load Up on Fruits and Vegetables

does flying dehydrate you

In our day-to-day lives, much of our fluid intake comes from the foods we eat. 

Fruits, vegetables, and cooked grains all hold plenty of moisture and help you remain hydrated in your normal life. In fact, if you follow the recommended guidelines of vegetables and fruits making up half of your diet, you’re adding an additional 2 cups of H20 to your daily intake[*].

The problem? Most of us don’t eat the way we normally would while we’re on the fly. 

We grab high-sodium, heavily-processed fast food at the airport while we’re rushing toward our departure gate. Or we skip a regular meal altogether in favor of nutritionally depleted plane food. 

So while your diet is normally full of more plants, when you’re traveling, those nutrient-rich leafy greens aren’t such a common occurrence. And no, the lettuce on the burger you picked up in the airport food court doesn’t count! 

Support hydration and digestion, nutrition, and overall wellness by ensuring you eat as healthfully (and normally) as possible when you fly. 

We chose to stack Flight Elixir with whole-food ingredients to support elevated nutrition and digestion.

#6. Pack High-Quality Topical Treatments

Most airline passengers feel the fluid loss from flying first via their skin and membranes. 

If you struggle with dry skin, chapped lips, peeling cuticles, a dry, tender nose, eczema flare-ups, or even nose bleeds when you fly, this is likely the culprit. 

Your first lines of defence should be what you consume (or not), such as increasing your fluid, electrolyte, carbohydrate, and plant food intake, and avoiding diuretics. 

But to tackle the problem from all angles, pack some topical treatments in your carry-on so they are handy both on the plane and off. 

We suggest packing a: 

  • High-quality facial moisturizer
  • Separate hand, foot, and body moisturizer
  • Multi-purpose balm or ointment like Vaseline  or chapstick to protect and hydrate your lips, inner nose, and cuticles 
  • Oil such as argan oil for your hair
  • A hydrating mist or toner.

Because dry skin is particularly sensitive, opt for a fragrance-free or natural fragrance product. Natural products without parabens, dies, or drying alcohols will be more effective and gentle than artificial alternatives. 

#7. Pay Attention to Humidity

Dry cabin air in your aircraft is one of the main contributing factors of dehydration when you fly. And unless your final destination is a humid one, you’d be wise to be mindful of the humidity levels of your accommodation. 

Consider packing a portable humidifier in your suitcase for use at your final destination. They’re small but effective, and it can run on the nightside table while you sleep to restore moisture in your body. 

When you check into your hotel or short-term rental, check out the heating and cooling systems in your accommodation for humidity controls. Consider turning off the air conditioning because it strips the air of moisture. 

And if those aren’t options? You can always run a warm shower to put some moisture back in the air. 

Sarah Peterson
Sarah Peterson

Sarah Peterson is the co-founder and head of marketing at FLIGHTFŪD. She's a travel health expert and after having visited 20+ countries as a digital nomad and flying every 4-6 weeks for business, she became passionate about empowering others to protect their bodies on the go.

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