Teton Vascular Institute

Healthy veins have one-way valves that keep blood flowing toward the heart, against the force of gravity. When these valves become weak and don’t close properly, they allow blood to flow backward, a condition called venous insufficiency or vein reflux.

Veins that have lost their valve effectiveness, become elongated, rope-like, bulged, and thickened. These enlarged, swollen vessels are known as varicose veins.