Updated October 2026. Written by the FinalMedic team, a Canadian medical supply retailer that fits and ships JOBST, Truform and other medical compression every day. This guide explains the system; it does not replace advice from your physician, pharmacist or certified fitter.
Compression socks and stockings are sold by pressure level, measured in millimetres of mercury (mmHg). The number tells you how firmly the garment squeezes at the ankle. Pick too low and you get little benefit; pick too high without guidance and the stocking can be uncomfortable or, for some people, unsafe. This guide walks through every level sold in Canada, what each one is for, when you need a prescription, how insurance treats them, and which JOBST line to look at.
The five compression levels at a glance
| Level | Also called | Typical use | Prescription? |
|---|---|---|---|
| 8-15 mmHg | Light support | Tired legs, long days on your feet, diabetic and sensitive feet (JOBST SensiFoot), light travel support | No |
| 15-20 mmHg | Mild, over-the-counter | Aching or mildly swollen legs, flights and road trips, standing jobs, pregnancy, early spider or varicose veins, prevention | No |
| 20-30 mmHg | Moderate, Class I, medical grade | Moderate varicose veins, oedema that builds during the day, after sclerotherapy or vein surgery, DVT prevention, pregnancy with significant swelling, mild lymphedema | Not required to buy, usually required for insurance |
| 30-40 mmHg | Firm, Class II | Chronic venous insufficiency, lymphedema, post-thrombotic syndrome, severe varicose veins, after a DVT, venous leg ulcer prevention | Recommended; follow a clinician’s advice |
| 40-50 mmHg | Extra firm, Class III | Severe lymphedema and advanced venous disease under clinical supervision | Yes |
Two things apply to every level. First, all medical compression is graduated: the pressure is strongest at the ankle and decreases up the leg, which is what pushes blood and fluid back toward the heart. Second, the number is the pressure at the ankle on a correctly sized leg. A stocking that is too small does not become “stronger compression”, it becomes a tourniquet; one that is too large delivers less than the label says. Sizing matters as much as level, so read our JOBST size chart and measuring guide once you have picked a level.
8-15 mmHg: light support
This is the gentlest level and feels like a firm regular sock. It is the right choice for people who want all-day comfort without a medical reason, and for diabetic or sensitive feet, where a non-binding, padded sock protects the skin. The JOBST SensiFoot knee-high, crew and mini-crew socks sit here. If your legs swell noticeably by evening, step up to 15-20 mmHg.
15-20 mmHg: mild, no prescription
The most common starting point. 15-20 mmHg relieves tired, heavy, achy legs, reduces mild end-of-day swelling, and is the level most clinicians suggest for flights longer than four hours, long drives, nurses and retail staff who stand all day, and pregnancy without a diagnosed vein problem. It also slows the progression of early spider and varicose veins. Available without a prescription in every JOBST line: shop 15-20 mmHg.
20-30 mmHg: moderate, the most prescribed level in Canada
20-30 mmHg is the first medical-grade class and the one physicians prescribe most often. It is used for moderate varicose veins, swelling that returns every day, after sclerotherapy, laser or vein-stripping procedures, for deep-vein thrombosis prevention after surgery or during hospital stays, for mild lymphedema, and for pregnancy with marked swelling or vein pain. In Canada you can buy 20-30 mmHg without a prescription, but most extended-health plans will only reimburse it with one on file, so get the prescription first if you plan to claim. Shop 20-30 mmHg.
30-40 mmHg: firm, Class II
At 30-40 mmHg the stocking is doing real medical work: managing chronic venous insufficiency, lymphedema, post-thrombotic syndrome, severe varicose veins, the months after a DVT, and the prevention of venous leg ulcers once an ulcer has healed. Wear it only on a clinician’s advice, measure carefully, and expect a firm pull when putting it on (a donning glove or stocking donner helps). Shop 30-40 mmHg. For an active venous leg ulcer, ask about the JOBST UlcerCare 2-in-1 system, a liner plus a 40 mmHg outer stocking designed to be worn over a dressing.
40-50 mmHg: extra firm
Reserved for severe lymphedema and advanced venous disease, and fitted by a professional. Most people who need this level are already under the care of a vascular or lymphedema clinic; FinalMedic can source custom and extra-firm JOBST garments on request.
Who should not wear compression without checking first
Compression is safe for most people, but ask a physician before buying 20 mmHg or higher if you have peripheral arterial disease (poor circulation in the arteries, cold feet, pain when walking that eases at rest), untreated congestive heart failure, diabetes with loss of sensation in the feet, an active skin infection or open wound on the leg, or severe skin fragility. In these situations the wrong level can cause harm, and the right level needs to be chosen by someone who can examine you.
Knee-high, thigh-high or waist-high?
The level and the length are separate decisions. Most swelling and most veins sit below the knee, so knee-high is the default and the easiest to wear. Choose thigh-high when swelling or veins extend above the knee, after a thigh vein procedure, or when a clinician specifies full-leg compression. Choose waist-high (pantyhose) or chaps for pregnancy, swelling that reaches the groin, or if you simply dislike thigh bands.
Which JOBST line for each level
| JOBST line | Levels | Best for |
|---|---|---|
| UltraSheer | 15-20, 20-30, 30-40 | A sheer, hosiery look for work and occasions |
| Opaque | 15-20, 20-30, 30-40 | Everyday wear that conceals veins and imperfections |
| Relief | 15-20, 20-30, 30-40 | Durable, unisex, budget-friendly medical stocking |
| forMen | 15-20, 20-30, 30-40 | Men’s ribbed dress-sock look |
| ActiveWear | 15-20, 20-30, 30-40 | Cushioned athletic sock for walking and work |
| Sport | 15-20, 20-30 | Running, gym, cycling; odour control |
| Style | 15-20, 20-30, 30-40 | Argyle fashion sock that hides the compression |
| SensiFoot | 8-15 | Diabetic and sensitive feet |
| UlcerCare | 40 (system) | Venous leg ulcer management |
For a fuller comparison of feel, durability and price, read JOBST UltraSheer vs Opaque vs Relief vs forMen, or browse all JOBST compression stockings and socks.
Prescriptions and insurance in Canada
No level of ready-to-wear compression legally requires a prescription to purchase in Canada. The prescription matters for reimbursement. Most private extended-health plans (Sun Life, Manulife, Canada Life, Desjardins, Blue Cross and others) cover medical-grade compression, usually 20 mmHg and above, when you submit a physician’s prescription that states the diagnosis and the compression level, plus a receipt that lists the product, the mmHg and the supplier. Typical limits are two to four pairs per year. Veterans Affairs Canada and the Non-Insured Health Benefits program for First Nations and Inuit clients also cover prescribed compression garments for eligible clients. Provincial plans generally do not cover ready-to-wear stockings, including RAMQ in Quebec and OHIP in Ontario, so check your private plan first. Our receipts carry every detail insurers ask for, and we can bill many insurers directly: see insurance coverage and assignment of benefits.
How to get the most from compression
- Put them on first thing in the morning, before your legs swell, and take them off at night unless told otherwise.
- Measure before you buy, in the morning, with a tape snug but not tight. Sizes are by circumference, not shoe size.
- Replace every four to six months of daily wear. The elastic fatigues and the stocking quietly stops delivering its rated pressure.
- Wash daily or every other day in mild detergent, no fabric softener, and air dry. Washing restores the fibres’ recoil.
- Use a donning aid at 20-30 mmHg and above if you have weak hands or a bad back. Rubber gloves alone make a big difference.
Frequently Asked Questions
What compression level should I start with?
If you have no diagnosed condition and want relief from tired, achy or mildly swollen legs, start at 15-20 mmHg. If a physician has told you that you have varicose veins, venous insufficiency, lymphedema or a clot history, follow the level they prescribed, which is usually 20-30 mmHg or 30-40 mmHg.
Is 20-30 mmHg medical grade?
Yes. 20-30 mmHg is Class I medical compression and the level most often prescribed in Canada. It can be bought without a prescription, but insurers normally require one to reimburse it.
Do I need a prescription for compression socks in Canada?
No prescription is needed to purchase any ready-to-wear level. A prescription is needed if you want your private insurance, Veterans Affairs or the Non-Insured Health Benefits program to pay for them.
Are compression stockings covered by insurance in Canada?
Most private extended-health plans cover medical-grade compression (20 mmHg and up) with a physician’s prescription and a receipt showing the compression level, typically two to four pairs a year. Provincial health plans such as RAMQ and OHIP generally do not cover ready-to-wear stockings.
What is the difference between 15-20 and 20-30 mmHg?
15-20 mmHg is mild, over-the-counter support for prevention and comfort. 20-30 mmHg is medical-grade therapy for diagnosed vein problems, post-procedure recovery and swelling that returns daily. It feels noticeably firmer and should be sized carefully.
Can compression socks be too tight?
Yes. A stocking that is too small, or a level that is too high for your circulation, can cause numbness, pain, skin marks or colour change in the toes. Remove it and re-check your size and level; see a physician if you have arterial disease or diabetes.
How long do compression stockings last?
With daily wear and proper washing, about four to six months. After that the fabric loses recoil and no longer delivers the rated pressure, even if it still looks fine.
Should I wear compression socks to bed?
Usually not. Graduated compression is designed for upright, active legs. Wear them during the day and remove them at night unless your clinician has specifically told you to sleep in them, for example after certain surgeries.