Flying is a terrible experience depending on who you ask. Cramped quarters, germs flying around, sitting for three hours (often more), and being suspended more than 30,000 feet above sea level can take its toll on a traveler. With the holiday season upon us, many people are flying a lot more than any other time of the year. Most of these travelers are unaware of the impact flying can have on their health. While most travelers are worried about air quality on an airplane, research suggests that “a continuously flowing combination of air from outside the cabin and highly filtered recirculated air” results in contaminant levels that are below levels that are considered safe. Other aspects of flying can lead us down an unhealthy road.

Sitting

There’s no way around sitting for most of the time we’re on an airplane. The walk to the bathroom is maybe 15 feet, and no one wants to be the person trying to stand up for long periods of time on a flight. Let’s say you’re taking a flight from New York to California (approximately 5 hours and 45 minutes). After three hours of sitting, our artery dilation drops by 50 percent, which causes a decrease in blood flow to our muscles, heart, and even the brain. Our only option for promoting good circulation during a flight includes constant trips to the bathroom even when nature doesn’t call. Boeing also suggests seated exercises, such as ankle circles, feet pumping, knee lifts, shoulder rolls, neck rolls, and overhead stretches.

Radiation Exposure

Ionizing radiation, such as radiation given off by X-ray machines, is generally avoidable in large doses. On the other hand, there’s no way to avoid cosmic radiation, a form of ionizing radiation that comes from space, when we’re on an airplane. Down on earth we only have to worry about very low levels of cosmic radiation, but at flying altitude we’re exposed to a lot more. Since cosmic radiation cannot be seen or felt, there’s no way of knowing when or how much we’re being exposed to. Like any form of radiation, cosmic radiation exposure is large doses should be avoided by limiting the amount of time we spending 30,000 feet above sea level.

Germs Everywhere

Airplanes can become a breeding ground for bacteria, with pillows and blankets that are rarely washed, recirculated air, and sitting next to other passengers who are potentially carrying on germs as well as their luggage. A study conducted by Auburn University found that disease-carrying bacteria can linger on surfaces in a commercial airplane for up to a week. Researchers concluded that E. coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA) can survive on an airplane’s seat-back pockets and armrests for up to 168 hours thanks to cabin temperature and humidity levels.

Dehydration

Just like we have to stay hydrated before running a race or competing in sports, all travelers should stay hydrated before their flight. Boeing describes the relative humidity in the cabin of an airplane during flight as “similar to a dry summer climate or to being indoors in the wintertime.” In addition to the cabin’s humidity levels, caffeinated coffee and alcoholic beverages that are sometimes needed to get through a flight can also contribute to dehydration during and after a flight. Make sure you’re drinking plenty of fluids before, during, and after flying to make sure dehydration doesn’t hit you during your vacation.

Flying Phobia

We all experience even a little bit of apprehension when it comes to flying. After all, it is an 800,000 pounds of machinery suspended in air, more than 30,000 feet off the ground, for three hours or more. Some flying phobias are more extreme than others, to the extent that people avoid flying all together and turn to cross country road trips. According to the Anxiety and Depression Association of America, almost 20 percent of the U.S. population reports that their fear of flying impedes on their work or social life. The majority of people who suffer from an intense fear of flying admit that flying is safe, but are more worried that their anxiety will overwhelm them during the flight.

Jet Lag

Even after the flight lands and we’re back on solid ground, the unhealthy side effects of flying continue to rear their ugly head. Jet lag is the result of our “biological clock” becoming disrupted by the switch in time zones during a flight. For every time zone we cross, it takes around one day for our bodies to adjust. The National Sleep Foundation said jet lag is one of the most common sleep disorders. Some treatment options for jet lag include getting a good night’s sleep prior to the flight, stay on our “home” schedule if we’ll be at our destination for less than 48 hours, and change to your “away” schedule as soon as possible if you’ll be staying there for more than 48 hours.