They're squeezing more and more passengers into coach these days. Photo from blisstree.com

Take heart, obsessive travelers: according to the Centers for Disease Control (CDC), more than 63 million Americans travel abroad each year, and the great majority of them never have any major problems.

Still, we need to pay attention to the risks of travel. A study released yesterday by doctors at Harvard University found that travel is associated with a 3-fold higher risk for blood clots, called deep vein thrombosis (DVT), with the risk increasing for each 2-hour increase in travel time.

The clots, which often form in the deep veins of the legs, may occasionally break loose and head for the heart or lungs, which may lead to heart failure or stroke (which may, in turn, lead to death). Lots of “maybes” in that chain of events, but still, we need to pay attention.

Any type of travel where you sit still for long periods can be potential dangerous, but flying seems to be especially problematic. It’s harder to get up and move around on a plane, your legs are often stuffed into a woefully small space (in fact, DVT is often called “economy class syndrome.”) And the air in planes is also very dry, raising the risk of dehydration.

Scary, to be sure. But the CDC offers some simple but effective steps to minimize your risk.

While traveling

1. When sitting for long periods of time, such as when traveling for more than four hours:

• Get up and walk around every 2 to 3 hours.
• Wear loose-fitting clothes.
• Drink plenty of water, and avoid drinking anything with alcohol or caffeine in it.

2. Exercise your legs while you’re sitting by:

• Raising and lowering your heels while keeping your toes on the floor
• Raising and lowering your toes while keeping your heels on the floor
• Tightening and releasing your leg muscles

Lifestyle changes that help you avoid DVT:

• Exercise regularly
• Maintain a healthy weight
• Don’t smoke
• If you have a family history of DVT, talk to your doctor about medication (anticoagulants) to prevent or treat DVT

At Airhealth.org you can download a handy wallet card that reminds you of how to avoid DVT.