Buying compression socks comes down to three decisions: how much pressure you need, what size fits your leg, and what style suits your daily life. Most people can walk into a pharmacy or order online without a prescription, but choosing the wrong pressure level or size can make the socks ineffective or uncomfortable. Here’s how to get it right.
Do You Need a Prescription?
For general use, no. Over-the-counter compression socks are widely available at pharmacies, medical supply stores, and online retailers. These are designed for everyday needs like reducing leg fatigue from standing all day, staying comfortable on long flights, or managing mild swelling.
Medical-grade compression stockings, which deliver higher and more precise pressure levels, are sometimes prescribed by a doctor for conditions like venous insufficiency, deep vein thrombosis, or lymphedema. A prescription can also help if your insurance covers the cost, since many plans reimburse only with a doctor’s order. But strictly in terms of purchasing, you can buy most compression levels without one.
Choose Your Pressure Level
Compression is measured in millimeters of mercury (mmHg), the same unit used for blood pressure. The number tells you how firmly the sock squeezes your leg at the ankle, where pressure is strongest. Higher numbers mean a tighter fit. Here’s what each range does:
- 8 to 15 mmHg (light support): Minimal compression for tired, achy legs. Good for desk workers or casual travelers who want a little relief. Widely available in retail stores.
- 15 to 20 mmHg (mild support): The lightest level considered medical compression. Useful for very early or mild swelling, air travel, building tolerance if you’ve never worn compression before, and prevention in at-risk legs (for example, after lymph node procedures).
- 20 to 30 mmHg (moderate, Class I): The most commonly prescribed daytime compression level. This is the workhorse range for managing mild to moderate swelling after treatment, post-surgical recovery, and daily maintenance of conditions like lymphedema in the arms or legs.
- 30 to 40 mmHg (firm, Class II): Reserved for more significant conditions, including stage II lymphedema that doesn’t respond to moderate compression, lower-leg lymphedema where gravity creates a heavier load, and combined venous and lymphatic disease. This level is often paired with flat-knit garments or adjustable wraps for better shape control.
- 40 to 50 mmHg and above (very firm, Class III+): Used only for severe lymphedema, significant tissue fibrosis, or cases that clearly fail at lower levels. These should only be worn after a clinical assessment.
If you’re buying compression socks for general comfort or travel, 15 to 20 mmHg is a safe starting point. If you’re managing a diagnosed condition, your provider will typically specify the level you need.
How to Measure for the Right Size
Compression socks that are too loose won’t deliver enough pressure. Too tight, and they can dig into your skin, bunch up, or restrict circulation. Every brand has its own size chart, so you’ll need a few measurements rather than relying on your regular shoe size.
Take these measurements first thing in the morning, before your legs have a chance to swell during the day:
- Ankle circumference: Measure around the narrowest part of your ankle, just above the ankle bone.
- Calf circumference: Measure the widest part of your calf muscle.
- Shoe size or foot length: Most charts ask for this as well.
If you’re buying thigh-high stockings, you’ll also need to measure around the widest part of your thigh and the length from the floor to your upper thigh. Compare your numbers to the brand’s specific size chart. Don’t assume a “medium” in one brand matches a “medium” in another. When you’re between sizes, many manufacturers recommend sizing up for comfort.
Knee-High, Thigh-High, or Waist-High
Knee-high socks are the most popular style and work well for most people. They cover the area where swelling and discomfort are most common, and they’re the easiest to put on and keep in place throughout the day. Research consistently shows that patients are more likely to wear knee-high socks correctly compared to thigh-high versions.
Thigh-high stockings cover more of the leg, which matters after certain surgeries or for conditions affecting the entire leg. A systematic review from the University of York found that thigh-high stockings may be slightly more effective at preventing blood clots in surgical patients, but the difference wasn’t statistically significant. The practical tradeoff: thigh-highs are harder to put on, tend to roll down, and people are less likely to wear them properly. An incorrectly worn stocking can actually be unsafe, creating a tourniquet effect where it bunches.
Waist-high pantyhose-style compression garments exist too, primarily for people who need full coverage of both legs or who have trouble keeping thigh-highs in place. They’re less common and typically more expensive.
For most buyers, knee-high socks are the practical choice unless a provider specifically recommends a longer style.
Materials and What They Feel Like
The fabric blend affects comfort, durability, and how hot the socks feel on your legs. Most compression socks use a combination of materials:
- Nylon and spandex: The most common blend. Nylon provides durability and resistance to wear, while spandex adds stretch for a snug, supportive fit. This combination keeps the sock in place without slipping or bunching.
- Merino wool: Naturally temperature-regulating, keeping feet warm in winter and cool in summer. Merino also wicks moisture and has antimicrobial properties that reduce odor. A good choice if you plan to wear compression socks all day or across seasons.
- Cotton and bamboo: Soft and breathable for everyday comfort, but less moisture-wicking than synthetic or wool blends. Better suited for lighter activity levels.
If you run hot or live in a warm climate, look for moisture-wicking blends. If durability is your priority, nylon-heavy construction holds up longest.
Putting Them On (and Tools That Help)
Compression socks are supposed to be snug, which means they can be genuinely difficult to pull on, especially at higher pressure levels. The trick is to gather the sock into a doughnut shape, slide your foot in, and then gradually unroll the fabric up your leg, smoothing out wrinkles as you go. Rubber dishwashing gloves give you better grip on the fabric and make this much easier.
If you have limited hand strength, arthritis, or reduced mobility, donning aids can help. Metal frame devices hold the sock open so you can step directly into it, then slide the frame up your leg. Sliding aids are fabric sleeves that reduce friction, letting the sock glide over your foot and ankle. These tools range from about $15 to $60 and are available at medical supply stores or online. If you’re buying 30 mmHg or higher compression, a donning aid is worth considering even if your hands work fine.
Where to Buy
Over-the-counter compression socks (up to about 20 mmHg) are stocked at most pharmacies, big-box retailers, and sporting goods stores. Online retailers offer the widest selection of brands, styles, and pressure levels, often with detailed size charts and return policies. For medical-grade compression (20 mmHg and above), medical supply stores and certified fitters can measure your legs in person and help you find the right brand and size. This is especially useful for your first pair.
Prices vary widely. Basic over-the-counter pairs start around $10 to $15. Medical-grade stockings from established brands typically run $30 to $80 per pair, sometimes more for custom-fit or specialty garments. If you have a prescription, check with your insurance, as many plans cover part or all of the cost for medically necessary compression.
When to Replace Them
Compression socks lose their elasticity over time, even with careful washing. Plan to replace them every 3 to 6 months. You’ll notice the fabric feeling looser or the socks sliding down more easily as the fibers wear out. Having two or three pairs in rotation extends the life of each pair and ensures you always have a clean one ready. When you reorder, it’s worth re-measuring your legs, since changes in weight, swelling, or muscle mass can shift your size.
Who Should Avoid Compression Socks
Compression socks aren’t safe for everyone. People with peripheral arterial disease, where the arteries carrying blood to the legs are narrowed, should avoid them entirely. The added external pressure can further restrict already limited blood flow.
People who have reduced sensation in their legs, from diabetes-related neuropathy or other causes, are also at risk. If you can’t feel whether the sock is pinching or fitting poorly, it could cause pressure sores or skin breakdown without you noticing. Anyone who is bedbound or uses a wheelchair should talk with a provider before using compression, since their circulation needs differ from those of people who are on their feet regularly.