How do cigarettes cause peripheral arterial disease?

Cigarettes / damage: Smoking cigarettes can damage the blood vessels a couple of ways. There is a direct toxic effect on the lining of the inside of the arteries and they also cause spasm of the arteries which worsens the narrowing.

Bad stuff: The key ingredient in cigarettes is nicotine. Our arteries have a muscular lining that can relax to increase flow and "squeeze" to reduce flow. Nicotine causes the lining to squeeze down and also causes damage to the lining which causes inflammation. Hard calcium is deposited which further narrows the vessels permanently reducing blood flow. This occurs in every artery when you smoke!