This morning I bent over to tie my shoe, and when I leaned back up in the chair I had an excrushiating pain in my mid-upper back. The pain hasn't gotten much better all day.
See your doc. I was in the ER with the same problem this weekend and they needed to rule out anything inside before deciding to look outside. Mid back pain can be anything from a heart attack to kidney stones to an aneurysm...or just an injured back. But rule out the dangerous before assuming it's the mundane.