Low oxygen may make you feel sleepy or headachyiStock/g-stockstudio
Millions of people travel by plane every single day. If you’re planning on being one of them soon, you might not be looking forward to the yucky feeling air travel often leaves you with. Besides the airport crowds and stress, traveling at such a high altitude has real effects on the body. Although the barometric pressure of the cabin is adjusted to prevent altitude sickness, you could still experience sleepiness or a headache. “The lower oxygen pressure found in an aircraft cabin is equivalent to 6,000 to 8,000 feet of altitude, similar to that of Mexico City,” says Paulo M. Alves, MD, global medical director of aviation health for the medical and travel safety services company MedAire. “Oxygen partial pressure drops accordingly, creating a mild hypoxia [low oxygen], which can cause headache in some susceptible individuals.” One study from the U.K. showed passengers’ oxygen levels dropped 4 percent, which could be a concern if you have heart or lung problems. To help prevent headaches, drink plenty of water, and avoid alcohol and caffeine. Here are some other ways to make sure you don’t get sick on a long flight.
Blood collecting in your feet could make them swell—or worseiStock/sshepard
Sitting in tight quarters for hours and hours can affect blood flow throughout your body, leading to swelling in your feet and ankles. It’s also well-established that the risk of a blood clot called deep vein thrombosis (DVT) increases when blood isn’t circulating well, as happens during plane travel. “In that position, the veins in our legs are compressed and the blood flow through them is slowed down,” Dr. Alves says. Although you often hear the advice to get up and walk around, Dr. Alves says that that can cause traffic jams if too many people do it at once, and can be dangerous in the case of unexpected turbulence. “Average travelers without any risk factors would benefit from simple movements of the ankle—rotation, flexion, extension—which can be done in their own seat as frequently as possible,” he says. Risk factors for DVT include being obese, pregnant or postpartum, on birth control pills, over age 40, or having a serious medical illness. “People with underlying risk factors for DVT benefit from compression stockings, and for some at high risk, even the use of anti-coagulant drugs may be indicated,” Dr. Alves says. Talk to your doctor if you have one or more risk factors and are planning a flight in the near future. Pay attention to these silent signs of deep vein thrombosis.