Compression stockings and sleeves come in different strengths, measured in mmHg (millimeters of mercury), the same unit used for blood pressure. The higher the number, the firmer the squeeze. The right level depends on your condition, how much swelling you have and what you can comfortably wear every day. Too little pressure won't control swelling. Too much can be painful, hard to put on or even unsafe.
How compression works
Medical compression garments are graduated. They're tightest at the ankle or wrist and gradually loosen toward the top of the garment. That pressure pattern helps push fluid and blood up and out of the limb instead of letting it pool.
The pressure range on the label, such as 20-30 mmHg, is the pressure at the ankle or wrist when the garment fits correctly. That's why proper measuring matters as much as the level itself.
Compression levels at a glance
Light, 8-15 mmHg: tired, achy legs and long days on your feet. No prescription needed.
Mild, 15-20 mmHg: travel, pregnancy, mild swelling and spider veins. No prescription needed.
Moderate, 20-30 mmHg: varicose veins, moderate swelling, mild lymphedema and after vein procedures. Usually needs a prescription.
Firm, 30-40 mmHg: chronic venous insufficiency, healed venous ulcers and moderate lymphedema. Prescription needed.
Extra firm, 40+ mmHg: severe lymphedema or swelling, usually custom-made. Prescription needed.
15-20 mmHg: everyday support
15-20 mmHg is moderate compression. Most people can wear it without a prescription, and it is the level many people start with. It is often a good fit for:
Tired, achy or heavy legs at the end of the day
Mild ankle and foot swelling
Spider veins or mild varicose veins
Pregnancy, when legs swell and feel heavy
Long flights or car rides, to help with swelling and lower the risk of blood clots
Nurses, teachers, retail and factory workers, and anyone who stands or sits for long shifts
Workouts, running and recovery
20-30 mmHg: firm, medical-grade support
20-30 mmHg is firmer and is usually recommended by a doctor or therapist for a specific condition, such as:
Moderate varicose veins or ongoing swelling (edema)
Mild lymphedema or lipedema
After vein procedures, or after a blood clot (DVT), when your doctor recommends it
Swelling that 15-20 mmHg has not controlled
Higher levels (30-40 mmHg and up), custom garments and compression pumps are used for more advanced lymphedema and venous disease. If that sounds like you, see our custom garments and compression pumps pages.
Ready-to-wear or custom?
Ready-to-wear garments come in standard sizes and are usually circular-knit. They work well when your limb has a fairly regular shape.
Custom garments are made from your measurements and are often flat-knit. They're best for lymphedema, lipedema, uneven limb shapes or when ready-to-wear sizes don't fit.
How to choose
Your doctor or lymphedema therapist will recommend a level based on:
Your diagnosis and severity. More swelling usually calls for firmer compression.
Your circulation. People with poor arterial circulation (peripheral artery disease) may need lower pressure or no compression at all. Your doctor may check this first.
Your skin and comfort. Fragile skin, pain or tenderness may mean starting lower and adjusting.
Your ability to put it on. Firmer garments are harder to pull on. Donning aids help, and some people layer two lighter garments instead.
Your daily life. Work, activity level and climate all affect which style and fabric you'll actually wear.
Check with your doctor first if…
You have diabetes, neuropathy, or poor circulation in your legs (peripheral arterial disease)
You have heart failure or skin wounds on your legs
Your swelling is new, getting worse, or only in one leg
If a garment hurts, leaves deep marks, causes numbness or tingling, or makes your toes or fingers change color, take it off and contact your provider.
Get care right away if one leg suddenly becomes swollen, painful, warm or red, or if you have chest pain or trouble breathing. These can be signs of a blood clot.
Getting the right size
Compression only works if it fits. Sizing is based on your measurements, not your shoe size. For the best fit:
Measure first thing in the morning, before swelling builds up.
Measure the narrowest part of your ankle, just above the ankle bone.
Measure the widest part of your calf.
For knee highs, measure from the floor to the bend of your knee while seated with your foot flat. For thigh highs or pantyhose, also measure the widest part of your thigh and the length from the floor to the top of the thigh.
Compare your numbers with the manufacturer's size chart. If you fall between sizes, or your calf is large for your ankle size, ask about full-calf or petite options.
Insurance coverage
Medicare covers prescribed compression garments for people with a lymphedema diagnosis. Coverage for other conditions varies by plan. We can help you check your benefits.
Local? Get measured and get it right the first time
If you live near Kalamazoo, Battle Creek, Grand Rapids or Lansing, our team can measure you and help you choose the right level, style and brand, from Juzo, Sigvaris, Medi, Jobst and L&R. Getting fitted helps you avoid the wrong size, saves time on returns, and makes sure your garment does its job. Contact us to set up a fitting, email customersupport@midwestcompression.com or call 800-883-1549.
Shop compression stockings
Browse knee highs, thigh highs and pantyhose in both 15-20 and 20-30 mmHg in our Stockings & Legwear shop, including sheer, opaque, athletic and men's styles.
This article is for general information and is not medical advice. Talk with your doctor about the compression level that is right for you.
