I've gotten the "pleurisy" diagnosis, twice even, and I don't believe it. Pleurisy seems to be the catch-all default diagnosis for when they can't find anything wrong and just want you to go away. There isn't actual evidence in favor of pleurisy, just the inability to find something else wrong.
In the first case, I'm pretty sure I had a panic attack. At least they served me bacon and eggs, probably hoping for a repeat customer with a real heart attack.
In the second case, I'm pretty sure I pinched a nerve in my back. I got shoulder pain associated with movement. I then got pain in the front -- but remember that a nerve pinched in one spot can cause pain to be felt elsewhere. Other back-related issues in the days afterward lead me to my conclusion.
I'm now way less inclined to go in to the emergency room. I don't want to spend 12 hours with an IV hurting my arm, no privacy, no sleep, and not being able to work on anything. One of the times the doctor even cleared me to go home, but the nurses didn't bother to remove the IV for hours afterward. Being in the emergency room isn't harmless; it is a place where diseases spread.