Compression Guide
Compression Guide
Which Compression Level Is Right For You?
Not all compression socks are the same. The level of pressure — measured in millimetres of mercury (mmHg) — determines what the sock can actually do for your legs. Getting the right level makes the difference between a sock that genuinely helps and one that just feels tight.
Here's everything you need to know to make the right choice — from a brand built by a surgeon.
First — how does compression actually work?
True compression socks use graduated compression — meaning they are tightest at the ankle and gradually decrease in pressure as they move up the calf. This gradient is what makes them therapeutic.
By applying the most pressure at the ankle, the sock gently encourages blood to move upward toward the heart rather than pooling in the lower legs. This reduces swelling, relieves heaviness and fatigue, and over time supports healthier circulation.
A sock that applies uniform pressure throughout — or one that is simply tight — does not provide the same benefit. Graduated compression is a clinical design, not just a tight fit.
The three compression levels — explained simply
Most people fall clearly into one of these three categories. When in doubt, start lower and move up only if your symptoms require it — or book a free virtual fitting and we'll tell you exactly what you need.
The gentlest therapeutic level — and the best starting point for most people. Provides meaningful circulatory support without feeling restrictive. Ideal for daily wear, travel, and active use.
This level is right for you if:
- Your legs feel tired, heavy or achy by end of day
- You stand or sit for extended periods — nurses, teachers, office workers, retail
- You travel frequently and want to prevent swelling on flights or long drives
- You're pregnant or recently postpartum
- You exercise and want faster leg recovery
- You have mild varicose or spider veins with no significant symptoms
- You're new to compression and want to start gradually
No prescription required. Available over the counter and suitable for daily wear by most adults.
Shop 15–20 mmHg →The most clinically prescribed compression level. Provides firm, therapeutic support for people managing moderate venous conditions, significant swelling, or recovering from medical procedures. This is the level Dr. Jean Segal most commonly recommends to his clinic patients.
This level is right for you if:
- You have moderate to significant leg swelling (edema)
- You have varicose veins that cause discomfort or aching
- You have been diagnosed with chronic venous insufficiency (CVI)
- You are recovering from sclerotherapy or vein treatment
- You have a history of deep vein thrombosis (DVT) or blood clots
- You are post-surgical and your doctor has recommended compression
- Your physician or pharmacist has recommended medical-grade compression
No prescription required to purchase. 20–30 mmHg compression socks are eligible for reimbursement through HSA (Health Savings Accounts) and FSA (Flexible Spending Accounts). We provide HSA/FSA-ready receipts with every order.
Shop 20–30 mmHg →The highest therapeutic compression level available without a clinical fitting. Designed for people managing significant venous disease, lymphedema, or severe swelling. This level provides substantial pressure and should be used under medical guidance.
This level may be right for you if:
- You have severe chronic venous insufficiency
- You have lymphedema or significant lymphatic dysfunction
- You have active venous ulcers or a history of venous ulceration
- You have been specifically recommended 30–40 mmHg by your physician
- 20–30 mmHg has not provided sufficient relief for your symptoms
We recommend speaking with your physician before starting 30–40 mmHg compression — particularly if you have arterial disease, diabetes with vascular complications, or any condition that affects lower extremity circulation.
Shop 30–40 mmHg →
"The most common mistake I see is people choosing a compression level that's either too low to be effective, or too high without understanding whether it's appropriate for their circulation. When in doubt — start at 15–20 mmHg, wear it consistently, and reassess. If your symptoms persist or worsen, come see us or book a fitting. We'll get it right."
— Dr. Jean Segal
General Surgeon with specialized training in vascular disease · Co-Founder, Dr. Johnny's
Not sure which level is right for you?
Book a free virtual fitting with one of our compression specialists — 15 minutes and you'll know exactly what to order.
Book a free fitting → Browse all compression4 tips for getting the most out of your compression socks
The right level only works if you're wearing them correctly. Here's what our clinic recommends:
Put them on first thing in the morning
Before your legs have a chance to swell. Compression works best when applied before swelling starts, not after.
Make sure the fit is right
Snug but never painful. If the sock is leaving deep marks or cutting off circulation, it may be the wrong size — not the wrong level.
Wear them consistently
Daily wear gives the best results. Sporadic use — only on long days or flights — limits the cumulative circulatory benefit.
Replace every 3–4 months
Compression fibres lose elasticity over time. When your socks stop feeling as supportive, it's time for a new pair — not a higher level.
HSA and FSA eligibility
20–30 mmHg and 30–40 mmHg compression socks are eligible for reimbursement through Health Savings Accounts (HSA) and Flexible Spending Accounts (FSA). These are pre-tax dollars — which means your compression socks effectively cost less than the sticker price.
When you purchase from Dr. Johnny's, we provide a detailed receipt with all the information your HSA or FSA administrator needs to process your reimbursement claim. Many customers use their annual HSA/FSA balance specifically for compression socks and foot care.
If your plan year is ending soon, this is a great time to use your remaining balance before it resets. Learn more about HSA/FSA →
Frequently asked questions
Do I need a prescription to buy compression socks?
No — all three compression levels are available without a prescription. However, if you plan to submit for HSA or FSA reimbursement, your plan administrator may require a Letter of Medical Necessity (LMN) from your doctor. Check with your plan before purchasing if you're unsure.
How do I know if the compression is too tight?
Compression socks should feel firmly supportive — not painful. If you experience numbness, tingling, skin discolouration, or significant discomfort, remove the sock immediately. This usually indicates the sock is the wrong size rather than the wrong level. Use our sizing guide or book a free virtual fitting before trying again.
Can I wear compression socks if I have diabetes?
It depends on your circulation. Standard compression socks can be worn by many people with diabetes — but only if lower leg circulation is not significantly compromised. If you have peripheral arterial disease (PAD), neuropathy with reduced sensation, or significant circulation issues, compression may not be appropriate. We recommend speaking with your physician. Our non-binding diabetic socks are designed specifically for diabetic feet and do not apply compression — they are a safe daily-wear option for most people with diabetes.
What's the difference between compression socks and diabetic socks?
Compression socks apply graduated pressure to support circulation and reduce swelling. Diabetic socks are non-binding, seamless socks designed to protect sensitive diabetic feet from pressure points and friction — without applying therapeutic compression. They serve different purposes, and some people use both.
How often should I replace my compression socks?
Every 3–4 months with daily wear, or when the socks no longer feel as supportive as they did when new. The therapeutic compression fibres lose elasticity over time, reducing their effectiveness. Many HSA and FSA plans cover compression socks as a recurring expense — so check your benefits before replacing at your own cost.
Can I wear compression socks during exercise?
Yes — 15–20 mmHg compression socks are excellent for running, cycling, and other activities that place sustained demand on the lower legs. They help reduce muscle vibration, support venous return during activity, and may speed up recovery afterward. Many athletes wear them both during and after training.
Ready to find the right sock for you?
Browse our full compression collection or book a free virtual fitting — we'll make sure you get it right the first time.
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