Understanding Compression Levels in mmHg

Every stocking carries a pressure rating in mmHg, and the temptation is to treat a higher number as a better one. This note sets the numbers the sources print against the caution they attach.

What follows is narrow. Only one publisher reviewed here gives an actual mmHg range, and it gives one.

The one number on the record

The Society for Vascular Surgery writes: "Knee-high compression stockings, usually that provide 20-30 mmHg of compression, will often help relieve symptoms such as aching or swelling." Two hedges sit in it. "Usually" qualifies the range, and "often" qualifies the relief.

That is a description of a typical stocking, not a prescription for your legs. It also names a knee-high length, so it says nothing about whether a longer stocking should carry the same pressure.

Tighter is a different category, not a better one

Cleveland Clinic says: "Very tight stockings require a prescription." The sentence draws a line without printing the number where the line falls. Where "very tight" begins is something the source does not state, so we will not guess it.

Vein Directory adds a comparison: "Non-prescription compression stockings may be successful in relieving the symptoms of varicose veins, although prescription stockings are usually tighter and more effective." Note the pairing. Tighter and more effective travel together in that sentence, with "usually" attached to both. For the clot-related background behind some prescriptions, see Cleveland Clinic on post-thrombotic syndrome.

What a pressure level commits you to

Choosing a level is choosing how firm the stocking feels every time you put it on. The sources reviewed here do not say how long to keep wearing a given level, or when to move up or down. That is a decision to make with whoever fitted you.

Before you pick a number

Ask what symptom the level is meant to address, whether the same level applies to the length you are buying, and when it should be reassessed. The Vein Directory piece on compression stockings is a general overview to read alongside those questions. Bring the answers to a clinician in Milford before you commit to a higher-pressure pair.