varicose veins

Meaning of varicose veins: The leg has to move blood uphill against gravity, and once the valves that stop it falling back give way, the vein stretches.

Definition of varicose veins

Varicose veins are surface veins of the leg that have become widened, lengthened and twisted, standing out under the skin as blue or purple cords. They form when the one-way valves inside the vein stop sealing, so blood that should travel upward toward the heart falls back and collects. The rising pressure stretches the vein wall further, and the process feeds itself.

Why do the valves fail?

Leg veins carry blood upward against gravity. They are helped by the calf muscles squeezing them with every step, and blood is kept from dropping back by paired flaps that open in one direction only. When a flap no longer meets its partner, blood slips down and collects in the vein below, a backward movement described as reflux. The extra volume stretches the wall, which pulls the next pair of flaps apart, and the failure spreads down the leg. Standing for long periods, pregnancy, excess weight, previous clots and advancing age all raise the pressure the valves work against, and a family tendency is among the strongest influences of all.

What else looks like them?

FindingAppearanceWhat it means
Varicose veinsBulging ropelike cords raised above the skinFailed valves in the surface vein system
Spider veinsFine red or blue threads flat in the skinTiny vessels, a cosmetic finding
Deep vein clotNo visible cord, but a swollen warm painful calfA separate and urgent condition
Venous skin changeBrown staining and hardening near the ankleLong-standing high pressure in the leg veins

Aching heaviness, itching, night cramps and swelling that builds through the day and settles overnight are the usual complaints. Appearance and symptoms match each other poorly, so prominent veins may be entirely painless while a leg with modest ones aches all day.

What complications follow?

Sustained pressure in the leg veins damages the skin those veins drain. Fluid escapes into the tissue as edema, the skin above the inner ankle darkens and thickens, and a shallow ulcer can open there and heal slowly. Skin in that state breaks down easily, which makes cellulitis more likely. A vein near the surface can clot and become a hot tender cord, and a knock over a thin-walled varicosity may bleed briskly because the pressure inside it is high. Procedures that seal, remove or close the failed vein work because the deep veins carry most of the leg's blood regardless.

Also known as

varicose veinvaricosities

Used in a sentence

Varicose veins were present in both legs with associated ankle swelling.

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Good to know

The size of a varicose vein tracks poorly with symptoms, and a swollen, warm, painful calf without visible varicosities points toward a clot in the deep veins rather than toward surface vein disease.

Word origin

Where “varicose veins” comes from

Varicose comes from the Latin varix, meaning a dilated or swollen vein.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.