If you’ve seen colorful knee-length stockings on your fellow air travelers lately, you may be spotting a pair of stylish (yes!) compression socks. Now offered in sporty or designer versions, they’re tighter-than-average socks that grow gradually looser toward the knee, worn by many passengers during flights. The idea is that they help circulate, or “milk,” the blood back up the leg to the heart, which can reduce swelling in your feet and possibly lower your risk of blood clots (also known as deep vein thrombosis, or DVT).
Because you can't move much while seated on an airplane and are restricted in a position that may compress the blood vessels behind your knees and at your hips, plus the fact that you may be dehydrated, it “can be the perfect storm” for DVT, says Amanda Zaleski, PhD, an exercise physiologist at Hartford Hospital in Connecticut who researches blood clots.
Some evidence suggests that the socks can help prevent DVT in the air. A 2016 Cochrane Review report of nine studies found “high-quality evidence” that “airline passengers wearing compression stockings develop less symptomless DVT.”
But there’s still not enough research on the subject to impress some physicians, including Elliott Haut, M.D., an associate professor of surgery with Johns Hopkins Medicine in Baltimore. Haut says that he nonetheless wears them when he flies — “not because there’s a ton of evidence, but because I’m in the, ‘Well, it probably wouldn’t hurt’ category."
Zaleski agrees that unless someone has certain health issues, “there are no established risks to wearing compression socks as long as they're properly sized.” The socks should come with measurement of compression level in millimeters of mercury (mmHg), like blood pressure, she says, and the average person would wear a pair with 15-20 mmHg.
Where can I buy compression socks?
RejuvaHealth. This company was founded by Kelsey Minarik, a woman who developed a blood clot on a cross-country flight, and offers lots of styles — sheer, argyle, houndsooth — at a range of compression levels. About $30/pair.
Vim & Vigr. Choose from designer compression socks in many colors and patterns (most 15-20 mmHg), with a wide-calf option. About $30 and up/pair.
SB Sox Lite Compression Sox. This brand is a well-rated and affordable option, with socks available in lightweight fabric (15-20 mmHg). $9 or $10/pair.
Travelers who shouldn’t wear compression socks include those with peripheral artery disease or diabetes, says Haut; be sure to check with your doctor if you’re unsure.
They can be harder to pull on than normal socks, so many people put them on before they board rather than struggle with them in their cramped airplane seats. Zaleski suggests wearers “roll the top all the way down, like you’re putting on hosiery, then put the foot in and roll them up.” Then you're good to take them off right after the flight, once you're mobile again.
More suggestions for avoiding blood clots while traveling:
- Wear loose-fitting clothing and adjustable shoes.
- Make use of cabin overheads to leave yourself plenty of leg room.
- Pass on the salty food, which can contribute to water retention.
- Move: Take a short walk every hour or so. Rotate ankles, point toes and flex calves while seated. Elevate feet whenever possible.
- Drink plenty of water to prevent dehydration. Drinking lots of fluids can serve as a natural “alarm clock” to ensure you get up every so often.
- Be cautious of sleep sedatives, which can result in sitting in one position for too long.