Topic 1: Understanding Pain

Pain is defined by the International Association for the Study of Pain, as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage”. This is the revised IASP definition as of 2020. Pain is one of the body’s important alarm systems, designed to protect us and warn us that we are under threat. When a person experiences pain, one of the most natural responses is for that person to give attention to where the pain is coming from, or discover what is causing the pain or threat. When you experience acute pain, the problem usually relates to local tissue injury, infection or inflammation. However, with chronic pain, the problem is often less strongly related to local tissues and involves a broader (systemic) problem.

In acute pain most of the “receptors” (called nociceptors) tend to be mainly localised at the site of any infection, inflammation or injury – the body’s systems are designed to recognise the injury or damage and coordinate the mind and body to favour recovery. In chronic pain, things change: there is growing involvement from other body systems (for example, the immune system, the sleep system, the hormonal system, the endocrine system). Changes occur in the way in which the nervous system interprets normal input or information: things that might cause pain normally, can cause much more pain and things that don’t normally hurt (e.g. normal daily movement or activities, gentle touch) can actually be painful. This is because the nervous system is not hard-wired but plastic, and the changes are due to the neuroplasticity of the nervous system and other systems, including the immune and endocrine systems. These neuroplastic changes in the nervous system contribute to ongoing pain.

While treatment and management of acute pain may be more focused on the immediate tissue injury or the illness initially, treatment and management for a person with a chronic pain problem must also address broader body-mind systems (for example, immune, nervous, hormonal, behavioural and emotional contributors to pain.

Credits: Credit: Joyce McSwan – PainWISE Pty Ltd.