H,i would like to know what causes sharp chestpain when one breathes in,it doesn't last for long and it feels more like it's on my skin than internal?

Sharp pains: In my experience such sharp,fleeting chest pains,especially if brought on by a deep breath, are caused by pinched intercostal nerve or muscle that runs between 2 ribs. Of course lung infections usually have associated cough and pleurisy is unlikely. This is more of a nuisance and usually resolves on its own after a few days. In the meantime avoid straining your rib cage. See your MD as needed.