Ask the doctors: Sitting still for too long could cause deep vein thrombosis

Dear Doctor: Is it really that important to walk around during a long flight? I always take a window seat when I fly, and I pretty much stay put because it’s so hard to move around in a plane these days.

Dear Reader: Experts suggest walking around during flights because of the risk of developing a blood clot in the legs, which can be life-threatening. While you’re seated, your legs are bent, and gravity is at work. Over time, your blood flow can become restricted enough to encourage the formation of a blood clot.

When a blood clot forms in the deep veins – the vessels we can’t see through the skin – in the lower leg or the thigh, it’s a condition known as deep vein thrombosis, or DVT. And although it’s commonly associated with air travel, deep vein thrombosis is a risk for anyone who stays seated in one position for hours at a time. That includes a flight of about four or more hours, a car trip, a bus ride or even a long session of sitting still at your desk.

Many people who experience deep vein thrombosis won’t even realize it occurred because the clot that formed will dissolve on its own. The risk arises when the clot, or a piece of it, breaks free and travels through the bloodstream. The clot can then become lodged in an artery in the lungs and block the flow of blood, a dangerous condition known as pulmonary embolism. Not only can this result in damage to the lungs, the reduction in oxygen levels can cause harm to organs and tissues throughout the body.

Symptoms of DVT include unusual warmth, swelling, cramping or pain in a thigh, calf, ankle or foot, often on only one side of the body. The pain associated with DVT sometimes may be felt only while moving or walking. There may also be a change in skin color, which can become unusually pale, or perhaps take on a blueish or reddish hue. These symptoms can appear days and even weeks after a clot has formed.

Symptoms of a pulmonary embolism include chest pain that increases while inhaling deeply or while coughing, rapid heart rate, dizziness, sweating, panting and blood in the sputum (saliva). If you have any of these symptoms, seek medical help. A physical exam and simple tests can determine whether a blood clot is the cause.

The good news is that you can take steps to avoid DVT while sitting for extended periods. First, stay hydrated. Drink lots of water, but no alcohol. Wear loose and comfy pants. Avoid crossing your legs at the knee. While sitting, do in-seat exercises, such as wiggling your feet, contracting your calf muscles, and lifting and stretching (as much as you can) your legs. Even better is to stroll up and down the aisle for a few minutes every hour, taking care to consciously stretch your legs and engage the large muscles. We understand that you prefer to stay seated, but DVT is a serious condition, and your health and well-being are at stake.