15 Things That Happen to Your Body When You Fly

Whether you travel all the time or once a year, you’re likely to experience the common and unpleasant sleep phenomenon of jet lag. Your internal clock becomes out of sync as a result of traveling in different time zones, which can affect your sleep and alertness. Daytime fatigue, insomnia, and mood changes are common symptoms.

Whether you’re in first class or economy, airplane ear will likely get to you; it does not discriminate. Remember the pressure inside your ears when a plane lands and takes off or when there is a sudden change in altitude? That’s airplane ear, or ear barotrauma. Muffled hearing and temporary mild hearing loss are common symptoms. Yawning, swallowing or chewing gum — a pacifier or a bottle of milk if you’re traveling with an infant — should take care of the problem.

Changes in elevation and atmospheric conditions can change how much cosmic radiation we are exposed to. In 2015, an investigation warned that a solar storm can trigger a shower of radiation that can affect people. The radiation, researchers say, is too weak to cause danger at ground level, but neutrons that don’t reach the ground do reach airline altitude. That’s why airplanes are diverted away from the North Pole during solar particle events — a lot more cosmic rays come down there.

Chances are you’ve had tomato juice on a plane — and only on a plane. United Airlines tried in 2018 to remove the drink from its menu but people revolted and the airline had to bring it back. There is a perfectly logical explanation as to why tomato juice (or a Bloody Mary) is the preferred drink of many travelers up in the air. The high decibel level in the plane plays with people’s taste buds. Also, taste receptors are less sensitive because of the low pressure in the cabin, causing less oxygen in the blood. Sweets are not felt as strongly, while savory tastes are heightened.

Blame it on the lack of air in a plane. The skin dehydrates as the air in the cabin is less humid. Some research has shown that flying can dry out the skin by as much as 37%. Dry skin is likely to be itchy. Oil gets trapped under the skin while it tries to secrete more to fight the dryness, possibly leading to pimples and breakouts. This is true for all types of skin. The so-called “airplane acne” usually disappears in a few days; it’s not a chronic condition.

Motion sickness is a common side effect of traveling and, contrary to popular belief, it happens to people who don’t only travel by sea or car. The body, the inner ear, and the eyes send inconsistent signals to the brain. Cold sweats, dizziness, headaches, and fatigue are common symptoms. Many student pilots experience motion sickness. But after a while they get used to the sensations of the flight environment and don’t have any issues.

Leg and foot swelling is very common during flights — you sit down too much, blood flow slows down and blood pools in your leg veins. That, combined with the extra pressure on your legs from sitting, leads to swelling. Most of the time this is harmless and is easily taken care of –“ just get up every hour or so and move around — and never wear tight clothing. People at a higher risk of swelling and experiencing complications from it are pregnant women and people who’ve recently had surgery or take certain medications.

Who hasn’t been embarrassed to open their mouth after waking up from a nap on a plane? Bad breath is a side effect of dehydration. Saliva, which has antibacterial properties, keeps the mouth clean and bacteria away. Chewing gum can help stimulate saliva production.

The reason you get dehydrated in airplane cabins is because of the low-humidity level. Jets draw in 50% of the air circulating in the cabin from the outside, and that air lacks moisture. The obvious answer is to drink more water and refill a water bottle often. You should also wear glasses instead of contact lenses and your carry-on should contain lotion, eye drops, and nasal spray.

Medical journals say there are studies that suggest jet travel appears to cause mood changes based on the disruption of the circadian rhythm. Though the medical community is not certain why this happens, enough research has been done to confirm that it does. The studies say these changes increase periods of depression for those traveling west compared with those with an elevated rate of manic/hypomanic episodes — this is associated with bipolar disorder — with eastward travel.

Cabin air pressure in jets is relatively low, and the amount of oxygen normally carried in the bloodstream is reduced compared with oxygen amounts at sea level. The change in air pressure is well tolerated by most passengers. However, those with medical conditions such as lung diseases and blood disorders may experience reduced oxygen levels, or hypoxia. Travelers with this condition are advised to tell the airline they are traveling on to arrange for an additional oxygen supply while flying.

Because travel disrupts your daily routine, it can affect your appetite as well. These changes cause your body to activate its fight response, releasing chemicals called catecholamines. The body reacts by temporarily closing appetite areas in the brain. Physicians suggest people do activities that are relaxing before they fly and avoid so-called trigger foods such as caffeine, alcohol, and exotic foods before traveling.

A change in bowel movements, sometimes called vacation constipation, is a common occurrence when people go on holiday. It can start while traveling because of limited bathroom access, and can continue because of a change in diet. To address this, before traveling, people should eat foods with probiotics (kimchi, tempeh and yogurt) because they contain good bacteria that helps digestion. During travel time, exercise and avoid snacks like chocolate and chips and instead eat high-fiber options like nuts and fruit. And drink lots of water.

Deep vein thrombosis (DVT) occurs when a blood clot forms in a large vein. Should the clot detach from the vein, it can travel to the lungs and block arteries to the lungs, causing what is called a pulmonary embolism. Travelers are at risk for this if they are sitting for a long time. People who are at increased risk are those who have had a previous blood clot, have a family history of blood clots, are obese, and are older. To prevent DVT, travelers are advised to wear medical compression stockings and take medication before traveling. They should pick an aisle seat and walk around every two to three hours while in flight. Travelers should also exercise calf muscles while seated.

Bloating is a common and uncomfortable effect from flying. There are several reasons why this happens. A change in air pressure in the cabin may cause gases within your body to expand, so experts advise travelers to avoid carbonated beverages and fatty foods. Remaining seated for hours at a time contributes to discomfort and passengers are advised to move around to reduce bloating. Drinking plenty of water keeps you from being dehydrated and will help with jet bloat.