Deep Venous Thrombosis (DVT)

Studies have shown that people on planes for longer than eight hours are at an increased risk of developing dangerous blood clots in the deep veins of the leg (DVT). There is a less significant, but still probable risk on shorter flights.

Blood clots that form in the deep veins of the leg can break off and travel to the lungs and the heart (Pulmonary Embolus) with the potential to cause a serious medical emergency. In addition to prolonged immobility, risk factors include: previous DVT, obesity, smoking, taking birth control pills, taking hormone replacement therapy, pregnancy, genetic factors, cancer, severe congestive heart failure, and recent surgery or trauma.

Furthermore, dehydration promotes blood clotting, and people often do not drink enough water while traveling. We recommend that if you are on a long flight or involved in prolonged sedentary activities, you should avoid alcohol and caffeine, as they cause dehydration. Moreover, drink plenty of water and take a walk every hour. If walking is impossible, flex the calves up and down a few times every 30 minutes. High-risk travelers may choose to wear elastic compression stockings to reduce the chance of developing DVT.

Note: DVT is not to be confused with dilated superficial leg veins (varicose veins), which have no risk of causing a Pulmonary Embolus, or blockage of an artery in the lungs.