A mild pain sometimes in left side back sholuder hands and sometimes in left foot triggers when i smoke.while smoking sometimes hands turn a bit blue

Varies: There are a number of considerations and probably starting with a good medical check up would be best. Smoking cigarettes will usually result in at least some degree of vasoconstriction in the arms and this can aggravate other conditions as well, even to the point that necrosis of the fingers can be seen. I would definitely recommend you be seen and evaluated.