Very rare. The vast majority of teenagers will not have blocked arteries. Rarely, heavy smokers develop buerger's disease, or thromboangiitis obliterans, a rare disease in which blood vessels swell and become blocked with blood clots. It usually affects men and women ages 20 to 40, but it is possible in teenagers! don't smoke!
Rare. Very unusual although vasculitis can occur at young age and cause symptoms of arterial occlusion.