Stabbing Pain in Left side of Back, Hurts when I take a deep breath

I have had a pain in the left side of my back about 3 inches up from the start of my ribcage that has really troubled me for 4 days now. The pain came out of no where when I was just sitting at work, which is wierd considering I play hockey and lift a lot of weights and it didnt begin when doing those activities. At first I thought it was a knot or muscle strain in my back but the pain started to change. I kept feeling a sharp pain almost convulsing pain, which I thought could be back spasms even though it wasn't in my lower back, it was a little higher up. The next day the pain subsided unless I took a deep breath or yawned, and the same sharp very concentrated pain would come back. To the point I almost couldn't finish sentences and I became short of breathe. Its hard to pin point a spot of the pain it seems like it is almost moving a little bit. It is very painful, but I can't seem to figure out what it is and and really have no idea. Has anyone had, heard of, or seen something similar or know what this is? Please help.

[bsmsl]

This sounds similar to what I experience with a dislocated rib which pinches a nerve and knots muscles up.  Many things can cause that kind of pain though..  I suggest you see your doc to see what he/she has to say.  

Feel better.

[David S. Wilson, MD, FCCP]

This needs to be evaluated.  Sharp pain that is not due to musculoskelatal sprain or strain can be serious.  You need to see a physician as soon as possible to exclude these serious potential causes that include blood clots or fluid around the lungs.

[littlemo1968]

i have been getting pains in my left side of chest and under arm it worsens sometimes when i inhale and exhale sharp stabbing pains leaves me breathless eases off for a while then comes back