Arteries carry oxygenated "nutritious" blood to veins carry the "used up" blood that has the cellular wastes back from the tissues to be cleansed.
Artery disease means that the tissues starve from lack of food. Vein disease means they cannot get rid of their wastes. Vein disease occurs from ankles to knees with ulcers, brown staining and swelling. Artery disease occurs at toes, bluish color/cold.