Let’s first look at how sitting and varicose veins affect each other. Varicose veins are formed when vein valves in the lower leg become weakened or damaged, causing blood to pool in the vein. The affected vein can swell and become painful, fatigued, restless, or itchy. When we sit for long periods of time, we’re minimizing circulation in the lower leg. Your veins aren’t given a chance to drain some of the pooled blood.