According to the Centers for Disease Control (CDC), long-distance flights may double or even quadruple the risk of developing a blood clot in a vein, known as deep vein thrombosis, or DVT. Such a blood clot can lodge in the lungs, a life-threatening condition known as a pulmonary embolism, or PE. The two conditions together are referred to venous thromboembolism (VTE), a disease that affects between 300,000 and 600,000 Americans a year, according to the CDC.
Studies show that it's not air travel itself that puts you at risk of a blood clot, however; it's being confined for long periods of time without moving. Therefore extended bus, train, and car rides can put you at the same risk. The longer your trip, the higher your risk.
Another thing most people don't realize is that it's not the amount of space you have that matters, it's how much time you spend immobilized. While you may have heard the phrase "economy class condition" used for VTE, research shows that VTE risk is the same whether you're in economy or business class.
There's no need for anxiety when you travel, however, as long as you take steps to protect yourself. Here are eight tips for preventing VTE while traveling.
1. Move around as much as possible, at the minimum every two to three hours.
During a flight, watch for the seat belt sign to be turned off, then stretch and take a stroll up and down the aisle. When space permits, stand for awhile at the back of the plane.
2. Book an aisle seat whenever possible.
This is a good idea both because aisle seats provide more room to stretch out your legs, and because when you have an aisle seat it's easier to get up and move around.
3. Wear loose-fitting clothing that doesn't impair your circulation.
4. When you can't stretch standing up, stretch in your seat.
The CDC recommends doing these stretch exercises:
- Stretch the backs of your calves by raising and lowering your heels with your toes on the floor.
- Do the opposite; with your heels on the floor, raise and lower your toes.
- Tighten and relax your leg muscles.
5. On long trips, consider wearing graduated compression stockings, which some studies have shown reduce the risk of VTE.
6. Be aware of your risk factors.
There are a number of things that increase your risk of VTE, among them heredity, being overweight, heart disease, pregnancy, and recent surgery. Make sure you know all the risk factors for VTE before traveling.
7. Discuss with your doctor whether it's beneficial for you to take aspirin or an anticlotting medication before flying. Experts recommend this for some people who are at particularly high risk for developing a blood clot, but it's not necessary for the general population.
8. Stay on the alert post-trip; most blood clots occur within the first one to two weeks after travel.
From there on, the risk decreases gradually; by eight weeks it will have returned to normal.