Recently I've Noticed That Sometimes When I Breathe Too Deep

Recently I've noticed that sometimes when I breathe too deep I get a sharp pain in my side and the back of my shoulder area. Also I play a musical instrument and it's been getting harder to play long phrases before I start to get out of breath. Do you think this is anything serious? I've been around someone who smokes basically my whole life so could that be the reason it's hard to breathe?