Compression Level Guide: Choose the Right mmHg for Your Condition
Graduated compression garments are measured in millimeters of mercury (mmHg) — the same unit used for blood pressure. The higher the number, the firmer the compression. The right level depends on your symptoms, condition, and whether a clinician has prescribed compression therapy.
Medical disclaimer: This guide is for educational purposes only and does not replace professional medical advice. Always consult a healthcare provider before starting compression therapy, especially at 20 mmHg or higher, or if you have arterial disease, diabetes, or neuropathy.
Compression Level Comparison Table
| Level | mmHg | Best for | Prescription guidance | Insurance coverage |
|---|---|---|---|---|
| Mild | 8–15 | Tired, achy legs; light travel; prevention | Over-the-counter | Usually not covered |
| Moderate | 15–20 | Mild varicose veins; pregnancy swelling; long flights | Over-the-counter | Usually not covered |
| Firm | 20–30 | Moderate varicose veins; edema; post-surgical recovery; DVT prevention | Often clinician-recommended | Frequently covered |
| Extra Firm | 30–40 | Severe venous insufficiency; lymphedema; active leg ulcers | Physician-guided | Usually covered |
| RX | 40–50 | Severe lymphedema or venous disease | Prescription-required | May be covered |
What Compression Level Do I Need?
8–15 mmHg — Mild
Use for everyday tired legs, minor swelling, or prevention during travel and long periods of standing. No prescription needed.
15–20 mmHg — Moderate
The most popular over-the-counter level. Helps with mild varicose veins, pregnancy-related swelling, and flight-related circulation support.
20–30 mmHg — Firm
The most commonly prescribed medical level in the United States. Used for moderate varicose veins, edema, post-surgical recovery, and DVT prevention after a clot. Discuss with your clinician before choosing this level.
30–40 mmHg — Extra Firm
For severe venous insufficiency, lymphedema management, and active leg ulcers. Wear under physician guidance.
Which Garment Style Should I Choose?
- Knee-high: Best for ankle/calf swelling, travel, and most varicose vein cases.
- Thigh-high: Use when symptoms extend above the knee.
- Pantyhose / waist-high: For full-leg or pregnancy support.
- Arm sleeve / gauntlet: For upper-extremity lymphedema.
- Wraps (e.g., FarrowWrap): Adjustable option for lymphedema or venous ulcers that may be easier to don than traditional garments.
See our How to Measure guide to get the right fit.
Is Compression Therapy Safe for Everyone?
Graduated compression is not appropriate for everyone. People with peripheral arterial disease, uncontrolled heart failure, or certain skin/nerve conditions should not use compression without medical clearance. Always check with your healthcare provider if you are unsure.
Will My Insurance Cover Compression Garments?
Compression garments are often covered by Medicare and private insurers when prescribed for qualifying conditions such as lymphedema, chronic venous insufficiency, and venous ulcers. We verify benefits, collect documentation, and file claims at no extra cost. Check your insurance eligibility.
Frequently Asked Questions
Can I wear 20–30 mmHg compression without a prescription?
20–30 mmHg garments are available over the counter, but clinicians typically recommend this level for diagnosed venous conditions. We recommend consulting a healthcare provider to confirm it is appropriate for you.
Is higher compression always better?
No. The right compression level matches your condition and comfort. Higher compression without medical guidance can cause discomfort or circulation problems.
How do I know my size?
Measure your ankle, calf, and thigh circumference (depending on style) first thing in the morning when swelling is lowest. Compare your measurements to the size chart on each product page.
References
- National Library of Medicine. Compression therapy for venous disease.
- Society for Vascular Surgery. Chronic venous disease and compression therapy.
- Centers for Medicare & Medicaid Services. Durable medical equipment (DME) coverage criteria for compression garments.
Byline: Pro Therapy Supplies Editorial Team
From our blog
- 15-20 vs 20-30 mmHg Compression Stockings: Which Level Do You Need? — side-by-side comparison of the two most-prescribed levels
- How to Choose Compression Stockings: A Complete Buyer’s Guide — level, style, fabric, and fit in one framework
- Compression Stockings for Varicose Veins: Which Level (mmHg) and Style Is Right for You? — which mmHg level fits varicose vein symptoms
- Compression Garments for Lymphedema: How to Choose the Right Level, Style, and Fit — why 20+ mmHg for lymphedema is a clinical decision
- Compression Stockings After Surgery: What to Expect and How Long to Wear Them — procedure-by-procedure wear schedules and mmHg guidance
- Compression Stockings for Leg Ulcers: What the Evidence Says — ABPI checks, 30-40 mmHg levels, and recurrence prevention