At one point I was having really bad lower back spasms that would drop me to the ground. The doctor said my L3 and L4 had degenerated and were starting to mix together (and he had the x-ray to prove it). The usual fusion surgery was recommended. Needless to say, since this was when I was working on my PhD, I bounced the issue off of one of the instructors who suggested I try an NLP technique called "reframing." Because all of the cells in your body are always being replaced (skin quickly, bones the slowest), this meant saying my disks were regenerating instead of degenerating. It took well over three years, but my issues went away. Then I blew out my rotator cuff and was back at the same doctor who asked how I had injured myself. When I said it was playing A-level softball he asked how I was even able to play with my back issues. After I told him what I did he wanted to take a new x-ray (which he paid for himself) and the first words out of his mouth when the x-ray arrived were "that's impossible!" Sorry Doc, but I really did regrow my disks!
Two things were learned: One, you have far more control over your body than you think and, two, doctors are great, but they don't know everything!