Buzz
If you remain seated for over four hours, blood clots could form in your legs. Although serious clots are uncommon, they can be life-threatening. The CDC advises that anyone embarking on long flights (or car trips) lasting more than four hours should take steps to lower their risk.
What’s the issue?
Your heart pumps blood throughout your body, but your muscles also play a crucial role in pushing that blood back toward the heart. Typically, this isn’t a concern—whether we walk around or simply move in our seats, the blood continues to circulate.
However, if your muscles remain inactive for hours—such as when you sleep with your legs crossed during a flight—blood circulation may decrease enough for a clot to develop in the deep veins of your leg muscles. This condition is known as deep vein thrombosis. While the clot may naturally dissolve over time, if it doesn’t, it can break free and lead to a pulmonary embolism, a potentially life-threatening condition involving blood clots in the lungs.
Before your flight
If you’re concerned about developing blood clots, it’s a good idea to consult a doctor before taking a long flight. Risk factors include:
Previous history of blood clots
Hormone replacement therapy or estrogen-containing birth control pills
Recent surgery, injury, or having a body part immobilized (e.g., a leg in a cast)
Pregnancy in the last 3 months
Varicose veins, obesity, or being over 40
Many of these factors are quite common, and as mentioned, clots are rare. However, if you have multiple risk factors or are particularly concerned, it's important to talk to your doctor. Some individuals at risk may need blood thinners, but unless you're at high risk, you'll probably just be advised to wear compression stockings and/or stay active during the flight.
Stay active and keep moving
Take breaks and walk around, especially on long flights. Even if you're stuck in the middle seat, your fellow passengers will likely expect you to take a trip to the bathroom at some point, so don't hesitate. Walk along the aisle and do calf raises by standing on your toes and lowering yourself back down.
In your seat, remember to stretch and move around regularly. Focus on your legs, as this is a common area for blood clots to form. Flex and extend your ankles, or try bringing your knee up to your chest if there’s space. For a more structured routine, try this 10-minute airplane seat workout; set a reminder on your phone to repeat it every few hours during long flights.
Recognize the warning signs of a blood clot
If you experience calf pain during the flight or in the following days, especially if it's accompanied by redness or swelling, don't ignore it. Should you also develop a cough or shortness of breath, make sure to get medical attention immediately.
