I injured my back in 91, have re-injured it numerous times since, now have degenerative disc disease along with that little old bulged disc. Testing in the last year with symptoms indicates sero-negative immflammatory arthritis, we assume since I responded so well to prednisone....
I have to assume the immune system goes haywire with all of us in some way, diagnosed or not! It's liking wanting to put a name to a face when they say "idiopathic" to me, it won't change things but at least I know what I'm up against.