Varicose veins are enlarged, swollen, and twisting veins, frequently linked to faulty valves in the vein and usually blue or dark purple in colour. Veins have pairs of leaflet valves to prevent blood from flowing backwards.] Leg muscles pump the veins to return blood to the heart against the effects of gravity. When veins become varicose, the leaflets of the valves no longer meet properly, and the valves do not work. This allows blood to flow backwards and enlarge the veins. This condition is most frequently seen in the legs but may also occur elsewhere. Typical symptoms are cramping pain and heavy limbs, leg swelling, venous eczema, skin thickening and ulceration. Varicose veins should not be confused with deep vein thrombosis, which is a distinct condition. The use of compressive calf sleeves or stockings may help to mitigate the symptoms of the condition.