02/16/2012 08:19 am ET | Updated Apr 17, 2012

Getting on a Plane? Don't Let the Hospital Be Your Final Destination

To my fellow road warriors, I have a question for you: What's worse for your health than a six-hour flight sitting in coach?

The Answer: A six-hour flight sitting in a window seat in coach, according to new guidelines from a group of expert doctors.

Just last week, I was on a packed cross-country flight, cramped in the middle seat. The gentleman next to me in the aisle seat was asleep most of the time, so rather than awkwardly trying to step over him to get out, I just stayed put. I'm sure you've been in the same situation and did the same thing. Honestly, I was uncomfortable, but was there any real harm being done? Maybe!

You may not realize it but when we're inactive for long periods of time, blood clots can form in the veins of our legs because we're not using the muscles that help blood circulate back to the heart. This condition, called deep vein thrombosis (DVT), is potentially dangerous -- a clot that gets dislodged once we get off the plane and start moving again can travel through the bloodstream to our lungs, where it could block the supply of vital oxygen to our blood. In very rare cases, a clot can make it all the way to the brain and cut off circulation.

So do passengers sitting in cramped economy class seats get DVTs more often than those in business or first class? The American College of Chest Physicians (ACCP) actually says no: There's no scientific evidence that your choice of cabin affects your risk of blood clots. What we do know is that long-distance travel, whether on places, trains, or automobiles, can raise your chances of DVT, especially for individuals who are at higher risk due to factors such as pregnancy, recent surgery, cancer or being on a contraceptive pill. It raises the risk because most of us are sitting on our butts the entire time sleeping, reading or talking. (Unless of course, we're in the "quiet car" on Amtrak, and believe me, you better not even whisper on the quiet car!)

Fortunately, most travelers are at an extremely low risk for DVT. The best prevention is as simple as getting your blood pumping again by leaving your seat and taking a short walk. Even when the "Fasten Seat Belt" sign is on, you can do easy exercises like flexing and extending your knees or gently rolling your ankles to minimize the blood pooling in your veins. You might have seen these exercises in the in-flight magazine, and some airlines are showing them as part of the initial safety video. They might look silly, but they are useful.

"Window or aisle?" It seems that many travelers enjoy sitting in a window seat. I'm not sure why, since you rarely see anything that is interesting. The reason to avoid the window seat on long flights, however, is simply because we tend to stay seated if there are two or three people we have to crawl over to get out. Sitting near the aisle makes it easier to get up, stretch out, and try those clot-busting exercises, ideally once an hour. And if you do happen to get the last seat on a flight and it's window, let your seat mates know that you'll be getting up, and they should too!

So the next time your captain says you're free to move about the cabin, take the advice -- it could save your life.

For more by John Whyte, M.D., MPH, click here.

For more on personal health, click here.

For more on new research, click here.