Why do we have pain?Pain is a phenomenon which occurs in a wide variety of medical conditions, but it also occurs in the absence of any physical problems. Pain warns us that something is wrong with our bodies and therefore we can act in certain ways to prevent injuries from getting worse. Of all psychical symptoms presented in practice, 50% of the symptoms are pain, 20-30% are respiratory related symptoms and 20-25% of the symptoms are non-pain and non-respiratory in nature, for example fatigue and dizziness. Pain can be defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage. Pain has a sensory and emotional component (fear and anxiety of developing pain and actual physical pain). Tissue damage is not necessary to experience pain: pain may occur in the absence of any physical problem. The two most frequently reported reasons for consulting a primary care physician are common colds, low back pains (in 85% of patients consulting for low back pains, only minor pathology is present) and headaches (usually no clear physical can be determined). How can pain be classified?Pain can be classified either according to cause or according to duration. According to cause there are four types of pain. Nociceptive pain is (musculoskeletal) pain due to tissue damage and causes pain in muscles, bones, joints and/or skin. For example a fracture, burn wounds or RA cause pain receptors to be activated and therefore cause the feeling of pain. Neuropathic pain is a consequence of damage to (or pathology of) the central/peripheral nervous system. It causes changes at the level of the nervous system to become permanent in nature over time and it therefore is difficult to treat. Many compare it to a sensation of needle pricks, electrical shocks, burning or freezing sensation or the sensation as if ants are crawling up and under their skin. Allodynia is when pain is...