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While blood clots may seem like something only suffered by individuals who aren’t in the best of shape, did you know that anyone can get a blood clot simply by sitting too long? Blood clots, also called deep vein thrombosis, can form during long periods of immobilization such as during an international flight. They most commonly occur in the thighs and lower legs. Blood clots can be dangerous because they can break off, travel to the lungs, and block blood flow which is known as a pulmonary embolism, if this occurs it is a life threatening situation.


Anyone can get a blood clot after sitting too long; however, certain conditions increase your risk of a blood clot. Such conditions include having had surgery in the last three months, cancer, history of heart failure, pregnancy, over the age of 65, or if you take certain medicines like estrogen or birth control. Your risk of a blood clot can also be increased if you smoke or are overweight.

Symptoms of having a blood clot include skin redness, swelling in only one leg, swelling or bruising behind the knee, localized soreness or pain, or having a warm spot on your leg. If the clot moves to the lungs you may experience shortness of breath, chest pains, a fast heartbeat, mild fever, or fainting spells.
Previously, it was recommended to all people to take low dose aspirin as prophylaxis while traveling long distance. The newest guidelines published by the American College of Chest Physicians in their Evidence-Based Clinical Practice Guidelines (CHEST guidelines), a well-respected publication that practitioners use to guide their anticoagulation decisions, no longer recommends low dose aspirin for all based on lack of evidence of aspirin’s ability to prevent DVTs. Doing away with this recommendation is an effort to reduce the number of patients receiving unnecessary therapies that provide little benefit and could have adverse effects. There is not sufficient evidence at this time to recommend everyone to take aspirin while traveling long distance.

Currently, the CHEST guidelines recommend stratification of risk. Therefore, patients who are at high risk of clots, i.e. have many of the previously mentioned risk factors would be candidates for an injection of low molecular weight heparin as prescribed by their practitioner while traveling. If a patient has never had a blood clot before and only has only a couple of the listed risk factors then the guidelines suggest those patients’ best option would be well-fitted, below-the-knee compression stockings at 15-30 mmHg of pressure and mobility/exercise throughout the journey. For someone with a low risk of clotting, the guidelines now recommend only mobility/exercise.

To stay safe while traveling, keep ahead of blood clots, and be sure to give your body a chance to stretch and allow your blood to flow.The main tip for avoiding travel-related blood clots is to not remain immobile for too long. Getting up and moving around throughout the journey is important. Exercises will help circulation and the following can be done while sitting: clenching and widening the toes, circling the foot clockwise and counterclockwise for each foot, and pressing the balls of your feet down hard against the floor to increase the blood flow in your legs. Also well-fitted compression stockings around 15-30mmHg of ankle pressure can be worn to help prevent clots. Pharmaceutical options can include low-dose aspirin (81mg) at the beginning of the flight or for high risk patients, low-molecular weight heparin may be an appropriate choice.

Guyatt G, et al “Antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines” CHEST 2012; 141(Suppl): 7S-47S.

by Lacie Rector