When knee-high is not enough. Thigh-high compression covers the whole leg, which matters when swelling or veins sit above the knee — the point at which a knee-high sock simply stops helping and can leave a band where it ends.
20-30 mmHg
Firm graduated compression, tightest at the ankle and easing all the way up. This is the level typically used for pronounced varicose veins, swelling that has not settled overnight, and post-surgical recovery when a doctor has asked for full-leg support.
Getting the fit right
Thigh-highs need two measurements — your ankle and the widest part of your thigh — and both need to be right. Too loose and the top rolls; too tight and it becomes a tourniquet at the thigh, which is the opposite of what graduated compression is for.
Before you buy
If you are diabetic, have peripheral arterial disease, or reduced sensation in your legs, speak to your doctor first. If it ever feels numbing rather than supportive, take it off.