When I exhale I get a sharp pain on the left rib cage what can this be?

Pain from rib cage. Osteochonritis: the rib is not bony all the way it attac to the sternum by mens of cartilage , a lot of time that cunction get inflamed and cause the pain, off and on.Some time could acute and some time turn to chrnic conditon.I t happen with people who suffer from asmtha, wieght leffting and other cause. Be carefull some time pain in that area could be heart problems?