ABSTRACT
Pain can be defined as an unpleasant sensation that is thought to originate from a particular body part and which is usually associated with processes that are capable of causing damage to body tissue. Pain can be acute, such as one might experience in the case of a fractured bone. If pain persists beyond the customary time it takes the affected part to heal or recuperate, the pain is termed “chronic.” Acute pain typically occurs when a noxious stimulus activates sensitive peripheral endings of primary afferent nonciceptors. The noxious stimulus is then turned into a form of electrochemical energy by a process called transduction, whereupon the message is then transmitted via peripheral nerves to the spinal cord and then on to the brain, where the inputs are modulated and pain is consciously perceived (reviewed in great detail by Fields, 1987). It is clear that pain is more than just a sensation. It has two components: sensory and affective. Regardless of the cause of the pain, both components must be considered.
