A condition known as deep vein thrombosis (DVT) can affect almost anyone who is stationary for extended lengths of time, such as on a long plane flight. Deep vein thrombosis occurs when blood pools in the lower extremities and begins to clot. Clots cause extreme calf pain with swelling -- or pain and swelling in any area of the leg or foot. As clots break loose, they can travel to the lungs, causing a secondary condition, known as a pulmonary embolism (PE), which is serious and life-threatening. You may be at risk if you've had a previous DVT, are a woman on hormone replacement therapy or certain forms of birth control, if you smoke or if you are obese. Individuals who have had recent surgery, or who have chronic diseases such as diabetes or cancer, are also at a higher risk. If you are predisposed to DVT or clotting in general due to a blood disorder, check with your physician first before flying.
Keep hydrated. Drink water, as dehydration can increase the risk of DVT forming. Avoid alcohol and caffeine, as these can increase dehydration.
Do exercises in your seat. Simple exercises done seated can help contract and release the muscles in the calves and thighs, which helps keep blood moving. Every half hour, straighten your leg, point your toes, and draw circles in the air. Repeat with the other leg. This works the calf muscles. You can also extend your leg, and push your heel forward, which stretches the calf. Then point your toe to contract the muscles. A second exercise is to straighten your leg from the knee, as if you were kicking the seat ahead of you. Bend your knee and straighten your leg several times. This works the big thigh muscles, keeping the blood moving.
Get up and walk. If you're allowed out of your seat, every hour or so, walk up and down the aisle. You'll get a chance to see other passengers, move your whole body and get your legs moving. Chances are even if you're healthy and fit, a walk every so often will help relieve the boredom of a long flight. But in the prevention of DVT, it's essential to get the whole body moving.
Buy compression stockings. If you have an underlying condition that may predispose you to DVT, purchase a pair of compression stockings at your pharmacy or medical supply store. The compression action of the stockings, combined with the previous steps, can help prevent DVT.
See your doctor before you fly. If you have had deep vein thrombosis or a pulmonary embolism in the past or have other significant risk factors, and are considering a long flight, see your doctor for advice on medication that can be administered before you fly. For example, injections of heparin, a medication that inhibits clotting, can be administered for some individuals. Aspirin may not have enough of an effect if you have a more serious underlying condition.
Know when to seek medical attention. Learn the signs of DVT and PE. Deep vein thrombosis can present anywhere from a few hours to a few days after your flight. Typically the calf affected is swollen, red and painful, particularly if the ankle is flexed, with the toes pointing up and the heel pushed down. Puffy ankles and feet that are not painful or red are usually fluid retention. Notice if your toes/feet are purplish-red, inflamed or painful as well. This could be a sign of clotting. Symptoms of a pulmonary embolism are pain in the chest or ribcage area and a feeling of shortness of breath when resting, both of which get worse when lying down. If you experience the symptoms of DVT, and particularly of PE, seek medical attention immediately.