AUTHOR: Dr. David Vivian
Pain, although usually a profoundly unpleasant experience, is a necessary part of our physiology. Those humans who are born without a pain system die prematurely, and at the end of their life, have substantial disfigurement. This is because they do not get the protection from tissue injury that pain provides, and also because the diagnosis of serious pathology, such as cardiac events and cancers, which typically present to doctors with pain, is delayed.
The pain system provides protection from tissue damage initially via the spinal reflex withdrawal system and subsequently from cognitive processes in which other controlled actions can be taken to avoid further tissue damage. For example, imagine you are walking along in bare feet and you stand on a sharp thorn. As the tip of the thorn touches the skin, sensitive receptors detect this information, and send nerve impulses up nerves in the leg to the spinal cord.