What Causes Lack Of Blood Circulation In Arms,hands And Legs?

i lose circulation in my arms, hands, feet, and my legs, extremely fast and i dont know why. i dont know whether its because im smoking and it constricts my blood vessels or because of my diet and exercise. all i know is that i cant lay down with my hands behind my head for more than 10 minutes without them falling asleep and then getting that pins and needles effect.