What causes a sharp pain under my left breast when i breath in? i went hiking on sunday and it was raining and i felt the pain monday morning.

C/p on breathing: Likely pleurodynia inflammation of lung membrane or costocondriitis 9 inflammation of the articulation of ribs) from viral infection. responds to motrin like products if not allergic - does it hurt when you press on the chest?then more likely it is costochondritis, or may be bronchitis rarely cardiac or vascular like clot. F/u/ w/ MD