You may have seen compression socks on a range of people — everyone from an older family member on bed rest to a seat mate on a long-haul flight to a neighbor training for a marathon.

And yet, says Dr. Robert H. Shmerling, Senior Faculty Editor at Harvard Health Publishing and former Clinical Chief of Rheumatology at Beth Israel Deaconess Medical Center, “There’s generally not consensus among the medical world that the average person needs to wear compression stockings.”

Who are they for, then? And how do they work?

What Are Compression Socks?

Compression socks are tight stockings that put pressure on your legs. Some go just to the knee, some above the knee, and others can go all the way up to your abdomen. Some compression socks work on a gradient, meaning their pressure is highest at the ankle and gradually decreases higher up the leg. Others have consistent pressure.

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Compression socks are intended to prevent and treat edema (swelling) and to prevent blood clots in the legs.

Benefits Of Compression Socks

The job of compression socks is to squeeze your legs, which in turn squeezes the blood vessels in your legs. The effect: better circulation, less swelling, and, perhaps, relief from leg pain.

Increasing pressure on your legs to help blood flow more easily may seem counterintuitive, but a quick primer on circulation can help. Whether standing or sitting, you spend most of your day upright, says Dr. Shmerling. In order for blood to flow against gravity back toward the heart, leg veins have special valves to help prevent it from going backwards.

“The way these little valves are designed, blood flow can only go in one direction,” explains Dr. Shmerling. “With the help of leg muscle contractions, blood goes through the valves, they close behind it, and blood moves in the correct direction toward the heart, and everything’s good.”

In some people, these valves fail over time — a condition called venous insufficiency. This causes blood and fluid to pool in your legs and make them swell. By squeezing your legs, compression socks help the valves in your blood vessels do their job.

Who Should Use Compression Socks?

Compression socks are a standard treatment for certain health conditions, such as chronic venous insufficiency, varicose veins, and edema in the legs. They are also used to prevent blood clots in the legs, known as deep vein thrombosis (DVT).

You may be more prone to leg edema and benefit from compression socks if:

• you’re obese
• you’re pregnant
• you have previous blood clots or injuries to your legs
• you’re bedridden.

But sometimes even healthy people deal with leg edema as their valves fail with age.

Your primary care physician can help you determine if compression socks could treat your edema or varicose veins, or prevent swelling or blood clots in the legs. They may suggest you see a vascular specialist.

There’s a widespread notion that wearing compression socks on long flights can prevent venous thromboembolism (blood clots in leg veins that can travel to the lungs). But this claim doesn’t have compelling scientific evidence to back it, except for people already at high risk on the ground.

If you’re a runner, chances are your social media algorithms have brought compression socks to your attention. Companies claim wearing these tight-fitting stockings during your workouts can reduce soreness and shorten your recovery time. But as popular as they may be among athletes, there’s not convincing scientific data to support their use in this way either, says Dr. Shmerling.

When To Wear Compression Socks

Typically, it’s best to put on compression socks when you first wake up and your legs are the least swollen, says Dr. Shmerling. You wear them all day but take them off at night while you sleep.

Because of their intentionally snug fit, compression socks can be difficult to put on. The following tips can help:

• Bunch the socks up and turn the toe inside out, then put your foot in, pull the sock over your heel, then work the rest of the sock up your leg.
• Use a powder like cornstarch or baby powder to absorb any wetness or sweat that can make it harder to get them on.
• Wear rubber gloves.
• Trim your toenails and smooth any rough skin patches to prevent snags.

A gadget called a donner that holds the socks open for you can also be a help if you struggle to get them on.

How To Choose The Right Compression Socks

You can purchase compression socks over the counter at medical supply stores and some pharmacies.

In some cases, you may need a prescription for them. For example, Dr. Shmerling explains that over-the-counter stockings may not work if you have very severe edema. A prescription may also be needed if you are planning to ask your insurance company to cover the cost.

If a prescription is needed, your medical team will measure your legs and make sure the size and pressure are right for your specific needs.

Important Notice: This article was also published at www.health.harvard.edu by Rachel Reiff Ellis where all credits are due. Reviewed by Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing