DEAR DOCTOR K:
A friend of mine recently developed a blood clot in his leg after a long flight. I travel a lot for work, so this has me worried. Is there any way to prevent this type of thing?
A blood clot that forms deep inside a leg vein, known as deep-vein thrombosis (DVT), can cause pain, swelling and redness in the affected limb. But the real threat happens if the clot breaks off and travels to the lungs. Known as a pulmonary embolism, this can lead to sudden death. I’ve put an illustration of this process below.
If you have to sit for several hours at a time on a plane or train, the following tips may help prevent DVT:Clots tend to form in blood when the blood is not moving much. They form in still ponds, but not in babbling brooks. Ordinarily, as you walk around, your leg muscles squeeze your veins and keep blood in the leg veins flowing back to the heart. If you are inactive for many hours, blood flow in the veins of your legs may slow so much that clots form.
- Get up and walk around every hour. I do this religiously every time I fly or travel by train. I always get an aisle seat so that I don’t disturb my seatmates.
- While sitting, flex and extend your ankles and knees every once in a while.
- Avoid crossing your legs. That pinches off even more of the flow of blood in your leg veins.
- Change positions often while seated.
- Stay well hydrated by drinking plenty of water.
Learn to recognize the signs of DVT. The affected area may be tender or painful, swollen, red and warm to the touch. If these symptoms linger for more than a few hours, call your doctor for advice. It’s very unusual for a person to develop DVT in both legs at the same time. So the signs of DVT are particularly important to bring to your doctor’s attention when they’re just in one leg.
Treating a DVT typically includes injections of an anti-clotting drug such as heparin, followed by additional anti-clotting drugs taken by mouth. People with less serious cases may need only anti-clotting pills. More serious cases may require powerful clot-dissolving medications given intravenously in a hospital.
If you have ever had a blood clot before, you may well be at increased risk for getting another one. So all of the advice I’ve given above goes double for you.
Very early in my medical training, I saw several patients die from blood clots in the legs that traveled to the lungs. One of them had been on a long airplane ride the day before. I don’t know if he had taken any precautions — he couldn’t tell me.
It made me decide that if there were any simple things I could do to protect myself from a similar fate, I would do them. I have, and you should too.