Im feeling pain in left side chest sinse 3 days I smoke cigrette once in 2 days but in recent days i smoked 7-8 cigrettes in 3 days and im feeling that pain everytime im smoking Also i had lower back pain recently is it because of that or because of smoking? I feel pain left upper lobe if pressed with finger and near heart and side of lung Is it serious. No difficulty in breathing or any other problem