Left rib cage is bigger than the right though it might just be because I used to lay on my side when I sleep and when I would Breathe the chest would not expand all the way or maybe it is a big heart or digestive system I'm not sure and thanks a what it could be we could probably because I used to lay on my side in when I would Breathe just want to expand all the way so I'm not too sure or maybe it is a big ass heart or digestive system I'm not sure and i can send pictures if needed and i am hispanic tho not sure if that helps common wise, also much thanks!