We cannot get understandable answers fast enough, cannot get substantial relief quick enough, but this very 'lofty' medical paper gives us a look inside the research side of our chronic pain syndrome, and though most of this is way over out heads, it gives you an idea of just how complex our illness is.
This addresses how the flood of substance P into our bodies not only cause pain, but look into the anxiety, depression, lack of sleep, stress response, sensitivities, and so many of the things we suffer. It gives us an idea of how the understanding of substance P has evolved over the years, beginning in the 1930's up to present day, and how many medical professionals are calling for a different type of drug.
http://www.medscape.com/viewarticle/409781_1
Here is the short version of this