Our veins, both superficial and deep, are the part of the circulation system, carrying blood back to the heart, against gravity through a series of one-way valves. If valves fail, the blood flows backward, increasing pressure in the veins. Over time these veins can become dilated, large, and twisty, progressively backing up into the normal veins and damaging them. This can cause aching, swelling, burning, and itching among other symptoms, or more serious complications. For many people, venous conditions can also be a cosmetic concern.