What Level of Compression Socks Do I Need for Flying?

Medically reviewed by Dr. Michael Darder OBGYN — Written by Kari Johnson

Published July 29th, 2020

Long flights can be a headache. If navigating your way through security and the terminal isn't hard enough, after you board the plane, you'll usually be confined to a small space. For passengers in economy class, it's not uncommon to find the person in front of you reclining into your lap. According to Time Magazine, "Less legroom is now the industry norm. In the early-2000s, rows in economy used to be 34 inches (86 centimeters) to 35 inches apart; now 30 to 31 inches is typical...Seats have narrowed, too, from about 18.5 inches to 17 inches on average." In such tight quarters, even extending your legs can be a challenge. 

Sitting for too long on a plane, train, or in a car can cause blood and fluid to pool in the lower legs and feet leading to swelling. We call this potato feet. 

Doctors recommend that all passengers walk up and down the aisles to promote blood circulation. Unfortunately, that's not always practical advice on crowded flights with frequent turbulence. Still, there's good reason for medical professionals to urge people to stand up during long-haul flights. Sitting in the same position for hours can cause major health problems with potentially deadly consequences. 

Luckily, compression socks offer support for frequent travelers. When you wear compression socks, you boost the blood flow in your legs. Not only does good circulation feel more comfortable, but it can also reduce your risk of developing dangerous blood clots. You may have noticed that many kiosks in airports sell compression socks with packaging that promises to eliminate aches, pains, and swelling. Seeing these, you may have found yourself wondering: Are these kiosk socks the best on the market? What should I look for in a pair of compression socks? What's the best compression level for air travel? In this article, we'll answer some of your burning questions and give you a few quick tips to make your next flight more enjoyable. 

How Does Compression Work?

Knee-length compression stockings and socks work by putting gentle pressure on the lower legs. The pressure narrows the circumference of the veins. Imagine a garden hose. The same amount of liquid traveling through a narrower vessel causes the velocity of the liquid to increase. The pressure forces your blood to move faster, improving your circulation. Veins transport deoxygenated blood from your lower extremities to your heart. Removing stagnant blood from the lower legs enables you to avoid that heavy, aching feeling that can occur when you stay in the same position for too long. Harvard Health Publishing summarizes the medical benefits of compression socks, explaining, "They're used to treat venous disease, heart failure, even deep-vein thrombosis."

When it comes to knee-high compression socks, there are two categories of compression on the market. Uniform compression offers a constant level of compression throughout the length of the sock. Graduated compression provides more pressure at the ankles and less at the calves. The gradient pressure works against gravity, forcing deoxygenated blood and waste fluid up the leg. A study in the British Journal of Surgery concludes, "Graduated compression stockings reduce the overall cross-sectional area of the limb, increase the linear velocity of venous flow, reduce venous wall distension and improve valvular function." (Agu) Fewer studies examine the efficacy of uniform compression as it relates to the prevention of chronic venous disease, deep vein thrombosis (DVT), and other medical conditions. Graduated compression socks have been shown to boost the circulatory system by assisting the veins in the efficient elimination of waste fluids from the extremities. 

What Are the Benefits of Compression Therapy for Airline Passengers?

Sitting for long periods can put you at risk for DVT, a condition that occurs when blood clots form in the deep veins of the legs. According to the Centers for Disease Control and Prevention, "900,000 Americans are affected each year by a blood clot, resulting in nearly 100,000 deaths." DVT was nicknamed "economy class syndrome" and "traveler's thrombosis" in 1977 due to its prevalence among frequent flyers. Within the scientific community, many question whether travelers'  blood clots result from immobility or from something related to air travel in particular. This is an area that medical researchers continue to study.

According to The National Blood Clot Alliance

...Anja Schreijer at Academic Medical Center and Leiden University Medical Center (Netherlands) investigated the issue further by comparing thrombin levels in air travelers versus immobile non-flying individuals who watched movies for 8 hours...They found a 223% rise in levels due to traveling compared to 46% rise due to immobility. This suggests that a mechanism other than immobility caused the travelers to be at an increased thrombotic risk. (Kos)

Whether air travel poses additional risks or not, frequent travelers should be aware that sitting for long periods in confined spaces, such as cars, buses, and trains, can put them in danger. By wearing compression socks, they reduce the likelihood that they'll develop deep vein blood clots. In turn, avoiding blood clots prevents the emergence of medical conditions including pulmonary embolism and post-thrombotic syndrome.

How Is Compression Graded?

All compression socks, whether you buy them in an airport kiosk or online, should be labeled with a compression level in millimeters of mercury (mmHg). The higher the mmHg level, the more pressure you'll feel applied to your leg. Graduated compression socks, the style recommended by most medical professionals for long-haul flights, should always include a label with a pressure range. For instance, you might see socks labeled 8-15 mmHg or 50-60 mmHg. When you look at a pressure range, remember that a graduated compression sock fits the most snugly at the ankle. Therefore, the higher mmHg measurement describes the pressure at the ankle. The lower number describes the pressure at the calf. 

Compression socks and stockings generally range from 8 mmHg (the lightest pressure) to 60 mmHg (extra-firm compression). You'll want to select a compression range based on the medical benefits you hope to receive. If your goal is to find the optimal compression for a long flight, it's helpful to refer to the medical literature. In a review of the existing studies of DVT in airline passengers, researchers aggregated results for passengers wearing both 10-20 mmHg and 20-30 mmHg graduated compression stockings, concluding, "...There is a highly statistically significant, large effect of wearing stockings compared to not wearing them, equivalent to the odds of a symptomless DVT being decreased by approximately 90%." (Clarke 15) Based on this evidence, airline passengers hoping to avoid DVT should wear socks with a pressure range that falls within 10-30 mmHg. 

Additional Benefits of Mild and Medium Compression

Doctors often recommend mild compression for first-time wearers. It’s a great option for anyone hoping to prevent leg and ankle swelling, varicose veins, spider veins, and achy legs.

Medium compression socks offer a number of health benefits. They relieve the symptoms of severe edema or lymphatic edema. Medium grade compression offers enough pressure for the management of active ulcers. In addition, symptoms of post-thrombotic syndrome (PTS), orthostatic hypotension, and superficial thrombophlebitis can be considerably reduced by applying medium compression. This is also an optimal compression level for athletic recovery and endurance.

The Compression Sweet Spot

The most popular style of Comrad socks, Companions, feature an amount of pressure that falls between mild and medium compression levels. Measuring 15-25 mmHg, these knee-high socks offer the best of both worlds. They're comfortable like mild socks, but they have the medical benefits of medium compression. We call the pressure range "the compression sweet spot," and for good reason! With Companions, your legs can count on a sweeter flight. Plus, by the time you get to your destination, you won't be walking around on potato feet. 

One of our customers, P.J., says it this way, "Unlike other compression socks, I don't want to take these ones off once the plane lands!" 

Erica C. agrees. In her review of the colorblock Companions, she explains, "I am writing from the plane ...a 14 hour flight from sfo>hk...My feet are less swollen than when I boarded this morning! They are awesome! I’m impressed."

Our team set out to create the best compression socks for travel, work, and exercise. We tested 145 prototypes over 2 years—variations of fabric, function, design, and compression—before landing on our first product, the Companions. Made with high-quality, antimicrobial, antibacterial SmartSilver fabric, these socks can be worn 3-5 times between washes. They're the perfect travel compression socks for experienced flyers, the people who know how to pack a suitcase to make every clothing item count. 

And the best part? No matter where your wanderlust takes you, your legs will always feel like they're traveling first-class. 

Additional Travel Tips to Prevent DVT

If you're looking for additional medical advice about ways to avoid DVT during travel, check with your doctor. For patients who are already at risk of developing DVT, pulmonary embolism, or post-thrombotic syndrome, it's common for doctors to prescribe anticoagulant medications for extra support during long-haul flights. 

The United Kingdom's Nation Health Service gives the following guidelines for anyone traveling:

  • Wear loose, comfortable clothes
  • Do calf exercises at least every half hour – raise your heels, keeping your toes on the floor, then bring them down 10 times. Then raise and lower your toes 10 times
  • Walk around whenever you can
  • Drink plenty of water
  • Do not drink alcohol or take sleeping pills ("Prevent")

Shopping for the Perfect Socks

Make sure your socks feel good—even when your economy seat doesn’t.

You'll find thousands of compression garments in airports and pharmacies, at medical supply stores, and on Amazon. Some styles, like knee-high compression socks, travel well. Other styles—open-toe, thigh-high lycra stockings—not so much. Remember, compression socks should be comfortable to wear, hour after hour, even when your flight gets delayed or you miss the last bus. Check reviews and see what people have to say about their experiences wearing compression socks during their travels. 

When you buy a pair of socks from Comrad, you have the ability to select your shoe size and calf width. In the correct size, your socks will apply the perfect amount of pressure to increase blood flow without pinching your skin. Socks that fit you well do a better job, keeping you comfortable for long periods of time, no matter where you're flying. 

Take a look at our favorite socks for air travel:

  • Nylon and spandex SmartSilver Companions—15-25 mmHg
  • Moisture-wicking merino wool Guides—15-20 mmHg 

Sources:

Agu, O., Hamilton, G., and Baker, D. "Graduated compression stockings in the prevention of venous thromboembolism." British Journal of Surgery, Vol. 86, Iss. 8, Aug. 1, 1999, pp. 992-1004. British Journal of Surgery Society Ltd., https://bjssjournals.onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2168.1999.01195.x.

“Are You At Risk for Clots?” Centers for Disease Control and Prevention, 7 Feb. 2020, https://www.cdc.gov/ncbddd/dvt/features/blood-clot-risk.html.

“Boosting circulation with compression stockings.” Harvard Health Publishing, Harvard Medical School, Nov 2013, https://www.health.harvard.edu/staying-healthy/boosting-circulation-with-compression-stockings.

Clarke  MJ, Broderick  C, Hopewell  S, Juszczak  E, Eisinga  A. "Compression stockings for preventing deep vein thrombosis in airline passengers." Cochrane Database of Systematic Reviews, Iss. 9, 2016, pp. 1-40, John Wiley & Sons, Ltd., https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD004002.pub3/abstract.

Kos, Cynthia A. “Air Travel and Deep Vein Thrombosis DVT.” Stop the Clot, National Blood Clot Alliance, 31 July 2018, www.stoptheclot.org/learn_more/air_travel_and_thrombosis/.

“Prevent DVT (Deep Vein Thrombosis) When You Travel.” NHS Choices, NHS, 18 Apr. 2019, www.nhs.uk/live-well/healthy-body/prevent-dvt-when-you-travel/.

Whitley, Angus, and Sybilla Gross. “Why Legroom on Planes Is About to Get Much Worse.” Time Magazine, Time USA, LLC, 26 July 2019, time.com/5636154/airplane-legroom-shrinking-asia/.