Back pain stem cell injection, page-128

What causes pain...

Tissue damage of magnitude significant enough will trigger the embedded nociceptive fibres. The nociceptive fibres send signals of 'damage' or 'threat' to the brain. The brain then mixes this data with a vast array of other data before you feel pain. Tissue damage alone will not cause pain... in anyone... ever. It's the brain that decides, strange as that may sound. But what causes pain isn't really the question to be asking (because most acute pain fixes itself without any intervention). The question to be asking is "what causes pain to drag on forever in some people?".

So that second question is far to big to even attempt to answer it here. But all the cutting edge research from around the world is focussed on the way the brain processes all those data streams I mentioned above. Stress and anxiety are huge factors. I'm not referring to the stress of having pain, I'm referring to basic personality traits which existed prior to the triggering incident.

The FDA will approve any old project, so long as it's conducted safely and ethically. That's their main concern.