In 1664 Treatise of Man, René Descartes described pain as a mechanical signal that traveled from the injured body part to the brain. This rudimentary model of pain is still the prevailing understanding amongst physicians. The science of neuroplasticity and nociceptive signal modulation have not quite yet influenced clinical thinking or medical teaching.
We now know that a nociceptive signal makes its way to our consciousness or not based on up regulation and down regulation at various levels in our peripheral and central nervous system and then is process in emotional context and rational context within our midbrains and cerebral cortexes respectively. The signal may be amplified or extinguished anywhere in this process. Also the perception of pain may be triggered without an initiating nociceptive signal. Such is phantom pain.
The Descartes model of pain transmission and perception does not give us enough understanding to have any hope of treating chronic pain. We have to embrace a new paradigm.