Definition of Pain
Pain is an unpleasant, sensory and emotional experience related to actual or potential tissue damage or described in terms of such damage.
This definition, by the International Association for the Study of Pain is the mostly widely used in academic circles and the most useful clinically.
It is worth remembering, however, that pain can also be used to refer to unpleasant sensations which do not have a direct connection with tissue damage, e.g. the pain of grief. Although this might be described as a metaphorical use, the two concepts appear to be more closely related than that implies. Patients sometimes prefer physical pain causing tissue loss to psychological pain connected with past trauma.
Pain always has an emotional colouring. It has repeatedly been shown that education about the meaning of pain can reduce the perceived intensity of the pain.(citation needed)