Pathophysiology & Conditions
Hypersensitivity as an identifying Feature
Chronic pain is a complex phenomenon. It results from a sustained sensory abnormality caused by an ongoing peripheral process such as chronic inflammation; however, it can also occur independently of the trigger that initiated it. A general distinctive feature is hypersensitivity, which can result from two principles: either the response to an injurious stimulus is increased, resulting in exaggerated and prolonged pain, or the thresholds are reduced, leading to pain production in response to normally non-injurious stimuli. In both cases, the responsive pain system is altered, resulting in chronic pain.1 The longer the pain lasts, the lower the chance of an entire normalisation of the nervous system. As a result, patients may develop a “pain memory”, leading to persisting pain although the injury has already healed.
1 Woolf CJ: Somatic Pain – Pathogenesis and Prevention. British Journal of Anaesthesia, 1995; 75:169-76
last update: 20 Sep 2012