Why Do You Get Dehydrated When Flying?

Why do you get dehydrated when flying?

You get dehydrated when flying mainly because the air inside the aircraft cabin is exceptionally dry, far drier than the air you are used to on the ground. With very low humidity surrounding you for hours, your body continually loses moisture through your skin and breathing, and that water is not readily replaced by the dry cabin air, so you gradually become dehydrated. This effect is compounded if you do not drink enough water during the flight and if you consume dehydrating drinks like alcohol and caffeine. The result is the familiar dry, tired, and thirsty feeling that long flights produce. Dehydration is one of the main reasons air travel can leave you feeling unwell, so understanding it helps you take simple steps to counteract it and arrive feeling better.

What makes cabin air so dry?

Cabin air is so dry because of where it comes from and how planes operate at altitude. At cruising altitude, the outside air is extremely thin, cold, and holds almost no moisture, and much of the air used to pressurize and ventilate the cabin is drawn from this environment, so it starts out very dry. As a result, the humidity inside an aircraft cabin is typically very low, often around 10 to 20 percent, and sometimes lower, which is drier than many deserts and far below comfortable indoor levels. The large volume of dry air circulating, combined with many passengers in an enclosed space, keeps humidity low throughout the flight. This dryness is an inherent feature of flying at high altitude, and it is the root cause of the dehydration and dryness passengers experience.

What are the effects of dehydration when flying?

The dry cabin air and resulting dehydration produce a range of noticeable effects. Most immediately, you may feel thirsty and develop a dry mouth and throat, along with dry, irritated eyes, which is especially bothersome for contact lens wearers, and a dry or stuffy nose. Your skin can feel dry and tight. Beyond these surface effects, dehydration can contribute to headaches, tiredness, and a general feeling of being unwell or sluggish, and it can worsen the fatigue and grogginess associated with jet lag on long flights. Mild dehydration is uncomfortable rather than dangerous for most healthy travelers, but it adds to the overall toll a long flight takes on your body. Countering it is one of the easiest ways to feel more comfortable in the air and better on arrival.

How do you stay hydrated when flying?

Staying hydrated on a flight is straightforward with a few habits. The main one is to drink water regularly throughout the flight rather than waiting until you feel thirsty; bring an empty reusable bottle to fill after security or ask the cabin crew for water. Limit alcohol and caffeinated drinks like coffee and some sodas, since they can contribute to dehydration and disrupt sleep. To combat surface dryness, use a moisturizer and lip balm, consider a saline nasal spray to keep your nose from drying out, and use lubricating eye drops, removing contact lenses on long flights if they get uncomfortable. Eating water-rich foods and avoiding overly salty snacks can help too. Starting well hydrated before you fly and keeping up your water intake in the air will leave you feeling far fresher when you land.