It’s more than just jetlag and popping ears.
When your flight touches down in another city, state, or country, it may feel like the journey is just beginning, but for your body, the adventure started when you boarded your flight (unless flight cancellations threw a wrench in your travel plans). Though it’s an effective and fast means of getting from point A to point B, flying the friendly the skies puts your system into overdrive.
From a change in altitude and pressure to an increased risk for certain ailments, there are a slew of fascinating (and a little wacky) things that happen to your body between takeoff and landing. Here, doctors reveal what happens when you’re miles high in the sky—plus solutions to ward off any unwanted side effects.
You will become dehydrated
There’s a reason many flight attendants will walk around throughout a flight offering water to passengers: Dehydration isn’t just common, it’s pretty much guaranteed when you fly. On a short, three-hour flight, you will lose 1.5 liters of water, says Ralph E. Holsworth, DO, a board-certified physician and the director of clinical and scientific research for Essentia Water. You’ll feel thirstier, but you may also notice your skin suffering. He recommends hydrating before, during, and after your flight, so you land without feeling parched. You can also use a moisturizer during and after your trip to ensure your pores receive the extra TLC they need.
Your ears experience stress
In addition to bringing on headaches or making you feel sleepy, extreme elevation can also be tough on your ears, says Janette Nesheiwat, MD, a family and emergency room doctor. This is even more intense if you are boarding a flight with a cold or sinus infection, since she says mucus and congestion build up with increased pressure.
Because of this, it’s ill-advised to take a long flight when you’re sick—not only do you put other passengers at risk, but Dr. Nesheiwat says prolonged periods of flying can lead to severe ear pain, hearing changes, or (at worst) hearing loss. If you’re healthy but still sensitive to these symptoms, chewing gum can be an effective way to make your ears pop, which releases some of the pressure.
You may feel sad
With your go-to playlist streaming, the sun shining from the pint-sized window, and your favorite travel clothes getting put to good use, you should be excited for your getaway…but do you feel a little sad? You may even feel a bit nostalgic without being able to wrap your head around the source. It could just be that you’re on a flight, according to Aaron Alexander, a movement coach, manual therapist, and author.
Airplane seats are formed to roll your spine into the position of a sad shrimp, he says, a postural pattern shown to reduce testosterone levels, allowing your body to access depressive memories more easily than normal. To cheer yourself up, Alexander suggests aligning your body by placing either a thick sweatshirt, jacket, pillow, or a small water bottle behind your thoracic spine—the area behind your heart—to reorient your spine to a more upright position while you’re in the air.
You have the potential to be exposed to radiation
Um, come again? Before you freak out and think about how many flights you have taken in the last year, breathe easy: it’s not as scary as it sounds. Medical expert Jill Carnahan, MD, ABIHM, ABoIM, IFMCP, and advisor at Tru Niagen, says that the first thing our body faces during takeoff is an increase in atmospheric radiation. This is a very natural thing, simply because we are away from Earth at an altitude of 30,000 feet or greater.
“Radiation causes DNA damage to cells and oxidative stress, similar to CT scans or X-rays,” Dr. Carnahan says. So what happens to our bodies? Not anything noticeable, especially if you only fly once a month or a few times every year, though Dr. Carnahan says pilots and flight attendants do have increased risks of radiation exposure because of how often they’re taking off and landing.
You will feel instantly tired—and may struggle to breathe
If you have a friend who falls asleep the moment you reach cruising altitude, there’s a biological reason why: cabin pressure. As Dr. Holsworth explains, oxygen levels are 75 percent lower when you’re in an airplane, which presents a laundry list of symptoms. These include drowsiness, as well an uptick in headaches or dizziness.
If you’re someone who suffers from heart disease or lung issues, flying can also increase your risk for hypoxia, which is a decrease in oxygen saturation of the blood, according to Dr. Carnahan. She suggests packing a small, carry-on air purifier to ensure you are breathing deeply from your diaphragm to prevent this.
You have an increased risk of blood clots
You have likely heard about the potential for blood clots when you’re jetsetting to a new place, but do you know why this happens? Dr. Holsworth says it’s mostly because you’re sitting for an extended period of time while going through lower atmospheric pressure changes. “The lost water content within the blood vessels increases the thickness of venous blood which is likely to pool in the lower extremities, thus increasing the risk of blood clots,” he says.
Sometimes, blood clots can be hereditary, so if your parents have suffered from them, it’s important to be mindful of your own risk. Dr. Holsworth says getting up from your seat when the seatbelt light isn’t on will keep your circulation flowing naturally. You can also invest in compression socks that work wonders, since they enclose your calves, helping blood move more easily.
Your legs may swell
Have you ever watched someone walk slowly off a plane with swollen ankles that seem unbelievably big? Alexander says this is usually caused by sitting for many hours, which allows fluid to build up in your lower extremities. Not as life-threatening or as serious as blood clots, it can still be super uncomfortable to suddenly have oversized legs. “You can avoid this by traveling with a pair of compression socks to help compress blood back up to the heart to be recirculated and prevent it from building up in your legs,” he says.
You’re more likely to get sick
There are some people who, no matter how hard they try or how careful they are, will catch a cold every time they fly. There are all sorts of factors involved in flying that impact your immune system, starting from the moment you arrive at the airport, Alexander says. In fact, he says airports are one of the most treacherous places for picking up unfamiliar germs. With so many people cycling in and out of airports, you never know what you may come in contact with, so it’s important to wash your hands frequently and be mindful of what you touch.
The same goes with airplane seats, since they often aren’t thoroughly cleaned between flights. The stale air and coughing, sneezing passengers make the likelihood of getting sick much higher. According to Seema Sarin, MD, a board-certified internal medicine physician, surfaces from the tray tables to the bathrooms are teeming with germs.
“The cold virus and bacteria, like E. coli, can live on these surfaces for up to a week. The only thing keeping you from getting sick is your immune system, which starts working harder to handle the germ overload,” she says. “Even then, you are 100 times more likely to catch a cold while on a flight.” To protect yourself, make sure to boost your vitamin C intake (think lots of citrus) before, during, and after your flight, and carry a natural hand sanitizer or some tea tree oil, Alexander suggests.
Your taste buds will go haywire
Chances are slim that you have ever described airplane food as amazing—but before you start to leave a negative Yelp review for an airline, Dr. Sarin says quality may not be to blame. It could actually be your own body reacting to being in an airplane. As you reach cruising altitude, the atmosphere in the airline cabin can decrease the ability to taste sweet and salty foods by 30 percent, she says. This leaves food tasting, well, bland.
“With the air constantly circulating through the ventilation system, your sense of smell can decrease due in part to the decrease in humidity,” Dr. Sarin says. “Complicating everything else, if you experience stress on the plane, this can contribute to literally leaving a bad taste in your mouth. All of this often results in a less-than-stellar dining experience.”