Commercial air travel causes a passenger's blood to become thicker and slow down, especially in the lower extremities which can increase the possibility of getting blood clots. The longer the flight, the greater the risk. Deep vein thrombosis (DVT) is caused by a blood clot forming in one of the legs. If this dangerous clot breaks off, it may travel to the lungs which could then be fatal.



A common misconception is that younger, physically fit athletes are less likely to develop deep vein thrombosis. Research indicates that many people with a slower, at rest blood flow, such as athletes, are actually more at risk than the general population. Having a history of swollen legs can also be a factor. Other people at risk are those that have or have had a serious medical condition such as heart disease, diabetes, or cancer. Also, women that are pregnant, or on birth control pills or hormone replacement therapy tend to be more prone to DVT. Obesity can also be a factor.

There are two sets of symptoms of deep vein thrombosis that you should be aware of. The first set of symptoms may appear during your flight or within the following couple of days. These symptoms are redness, swelling, tenderness or cramps in one of your lower legs, or some swelling or bruising behind one of your knees. The more severe symptoms usually appear two or more days after a blood clot has formed. They are fainting, shortness of breath, rapid or painful breathing, chest pain which can be accompanied by pain in the shoulder, coughing up blood, and a fever.

What can contribute to these symptoms?

Deep vein thrombosis can occur in your lower legs anytime you are sitting in one position for a long time without moving. Some research shows that you are at three times the risk of developing this serious medical condition when you fly. Driving, traveling by bus or train, or even sitting in your favorite easy chair at home can also cause it.

How can you, as an airline passenger, prevent this life-threatening condition from happening?

You can help prevent DVT from developing by increasing circulation in your legs. If you are predisposed to any of the above risks you may want to book an aisle seat to give you a little more room to move and enable you to get up and walk around at anytime without disturbing your fellow passengers.

Some experts suggest you wear loose clothing and avoid wearing tight fitting slacks, and elastic support socks or stockings; moving and exercising your legs frequently when sitting; changing your sitting position often; not sitting with you legs crossed; walking up and down the aisle every half-hour or so and drinking a sports drink such as Gatorade so you do not become dehydrated.

It is very common for deep vein thrombosis to be misdiagnosed which could be fatal. If you develop any of the above symptoms you must seek medical help immediately. Inform the doctor who is treating you that have just flown recently and you think that it could be a blood clot. If he doesn't believe it is deep vein thrombosis, ask him to order an ultrasound of your leg to be sure. If you are experiencing chest problems insist that he to do a simple and painless blood oxygen measurement on your finger. It only takes a couple of minutes and will prevent a serious misdiagnosis of your condition.

AirHealth.org, is an excellent, non-profit organization that is dedicated to your health when you fly. There is a lot of valuable, up to date information and research on their website about deep vein thrombosis that could save your life. They also have a free, wallet-sized flyer that you can download and take with you when you fly. It is available in English, French, and Spanish.