So, what is the purpose of pain?  If it’s a poor indicator of degree of damage, and you can have pain without damage, what’s the point?  Pain is there to warn you not to bend your finger back any further or to keep your hand on the hotplate on the cooker – it’s an alarm system.  Pure, but not simple.  Pain is the sensory output from an alarm system, pointing us to the original source of nociception.  It triggers automatic responses in us related to the fear/flight/fight response.  If you don’t take some physical action in response to pain – for example you continue to sit at your desk and suffer  – the increase in stress hormones will add to your agitation, and pain.  We need to respond to pain by doing something physical, and there is no response more appropriate than movement, so remember – use it or lose it, but don’t abuse it.