Veins vs. Arteries: Understanding Size and Function

Veins are generally wider than arteries.

Arteries carry oxygenated blood away from the heart to the rest of the body, while veins carry deoxygenated blood back to the heart. Since deoxygenated blood contains more carbon dioxide, veins need to be wider in order to accommodate the larger volume of blood. Additionally, veins have thinner walls than arteries, which also contributes to their wider appearance.