One in three Norwegians experience long-term or chronic pain, and around 50% of disabled people have chronic pain. Pain is defined by The International Association for the Study of Pain (2020) as an unpleasant sensory and emotional experience that is associated with actual or potential tissue damage, or described in such terms. There are three types of pain: nociceptive pain, inflammatory pain and neuropathic pain.
- Nociceptive pain - Created by activation of the nociceptive nerve fibers that send pain signals to the brain. Felt in response to intense stimuli, triggering an automatic protective response to avoid danger. For example, when we come into contact with something that is too cold, too hot or too sharp, we automatically withdraw the exposed body part to protect ourselves.
- Inflammatory pain - is caused by the immune system in response to tissue damage or infection, which aids in the healing process by deterring physical contact and movement.
- Neuropathic pain - is caused by abnormal function of the nervous system and can occur after e.g. illness or other diagnosis, without injury or inflammation.
All types of pain are generated by complex brain processing and influenced by various physical, psychological and environmental factors. Interestingly, how pain is perceived does not depend solely on whether there is an injury or not, which is known as the 'pain paradox'. Fortunately, plasticity allows the brain to be trained by forming new connections.