Preventing blood clots while traveling

VOL 117 / NO 1 / JANUARY 2005 / POSTGRADUATE MEDICINE

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If you take long trips by plane, you have probably seen in-flight videos about the importance of occasionally leaving your seat. Avoiding prolonged sitting while traveling by airplane, bus, train, or automobile can help prevent an uncommon but potentially dangerous condition called deep venous thrombosis (DVT). This disorder may occur during travel or several weeks later.

What is DVT?
DVT involves a blood clot that forms in a leg or, less commonly, the pelvis. A clot that forms below the knee may not cause any problems. However, one that develops above the knee is more likely to break away and move through the bloodstream to the lungs, where it can cut off the oxygen supply and lead to lung damage. A moving blood clot is called an embolus and can occur in a leg vein of someone who sits for long periods.

What causes DVT?
In the case of travelers, DVT occurs when blood isn't able to flow the way it should in a leg, either because a vein is damaged or because the leg is bent in such a way that blood can't flow freely. In general, DVT most often occurs in people who are older than 40 years or obese. Women who are pregnant, have recently given birth, or are taking birth control pills or estrogen hormone therapy are also at risk.

What are the symptoms?
Pain, swelling, warmth, and redness in only one leg can be symptoms of DVT. If these symptoms occur, seek medical attention quickly. If you also have shortness of breath or chest pain, call 911.

How is DVT treated?
If the blood clot is small and superficial (just in the skin) or is below your knee, it may only need to be monitored by your doctor. You may be advised to wear compression stockings and to elevate your feet while resting. If the clot is large and above the knee, you may require a drug that prevents clotting (sometimes called a blood thinner) or a medication that helps dissolve clots.

How can I prevent blood clots while traveling? Several things will help keep blood flowing freely while you travel. When in an airplane, bus, or train for longer than 3 to 4 hours, stand up and take a short walk down an aisle every hour. If this isn't convenient, do some light leg exercises, such as bending the toes toward the knees and then relaxing them or pressing down on the balls of the feet while raising the heels. When traveling by automobile for more than 3 to 4 hours, stop every hour and take a short walk. Avoid taking sleep aids. Wear loose-fitting clothing. Keep your legs uncrossed. Drink at least the same amount of water that you do any other day. If you are at risk for a blood clot because of a medical condition or a drug you are taking, your doctor may want to give you a clot-preventing medication before you leave. Consider wearing graduated compression stockings during the trip.

This information is not a substitute for medical treatment.