Anyone know what's wrong with me? I get this stabbing intense pain in my left side (at my ribs) whenever I try to take a deep breath (including yawning, sneezing, laughing - anything that requires a deep breath). It's so intense that I'm usually cut off short - my yawn isn't complete, my sneeze is half-hearted, etc.

Anyone have a clue what this could be? It came on suddenly Friday night and is still going on. Besides the pain when breathing deeply, I feel totally fine. I can breathe normally, just not deeply (and probably because of that, I feel the urge to take a deep breath constantly and can't).

Help!