The "aching sensation" could be caused by muscle tension in the chest. And it could be relieved by the relaxation provided by smoking. If the ache persists, at a minimum, you should have a chest x-ray.
You should also do your best to stop smoking cigarettes, if you are to avoid the risk of seriously damaging your lungs.
go and see your doctor, its most likely from SMOKING, while your at the doctors ask him for help to stop smoking, BEFORE ITS TO LATE, don't end up like most of us on here,
there is no BENEFIT from smoking, but THERE IS FROM NOT SMOKING,
do yourself a favour and get of the ciggaretts NOW before you damage your body
I am only 29 and wish I never picked up smoking. Quitting is the best thing you can do for yourself. It can cause breathing problems trust me you don't want to suffer through.