Veins are flexible, hollow tubes with flaps inside called valves. The valves open and close to allow blood to move in one direction toward the heart. Veins become larger and larger as they get closer to the heart. The superior vena cava is the large vein that brings blood from the head and arms to the heart, and the inferior vena cava brings blood from the abdomen and legs into the heart.
Treatment of venous disease includes medications, procedures and surgery.