PAIN is reliable in an unreliable way

The guys at The University of South Australia have put a great deal of work into the study of chronic pain.

Acute pain (as we might experience when we step on a nail or twist an ankle) is straight forward.  Do this - get that.  But what about pain which persists?  And what about pain which comes and goes or changes it's nature and location?  Confused?  Welcome to the world of chronic pain and the way it colours injury and dysfunction.

Health professionals still overwhelmingly deal with pain as if it were acute and something was damaged or broken.  Patients who present with continuing pain are told that their nerves are still healing or perhaps they have re injured the injury.  Is this accurate?

Chiropractors tend to see people with chronic or long term complaints.  Their problem often began yrs before but in the early stages their pain and dysfunction was brief and self limiting.  Furthermore it was aggravated by specific things, usually an awkward movement such as lifting and twisting.  Recently though the patient reports that their pain came from "nowhere".  "I slept wrong", "It just went out and now it's not going away".  In short their brief, self limiting problem has become chronic, 'unstable' and aggravated by trivial movements.  Additionally the pain has changed. It was sharper and "here".  Now it's sometimes sharp, often a dull ache or burning and it's spreading.  It feels like it could just "go" on me.

The patient has developed chronic pain.  The brain learns and changes through repetition and the repetition of pain can do interesting things with a plastic or moldable neurology.  Pain itself is a complex experience suffice to say it's important to pin down what originally triggered the problem (the disc, joint, bone, distortion - the diagnosis) and what may have led to it weakening (usually a combination of injury, sensation disturbance, lifestyle and of course genetics/epigenetics).

Ref   Apkarian et al. (2004) Chronic back pain