What is the neurophysiologic classification of pain?
The neurophysiologic classification is based on the inferred mechanism for pain. There are essentially two types: (1) nociceptive, which is due to injury in pain-sensitive structures, and (2) non-nociceptive, which is neuropathic and psychogenic. Nociceptive pain can be subdivided into somatic and visceral (depending on which set of nociceptors is activated). Neuropathic pain can be subdivided into peripheral and central (depending on the site of injury in the nervous system believed responsible for maintaining the pain). Although the term has been used for many years, psychogenic pain is a very vague term that should be reserved for only those instances in which one has conclusively excluded all nonpsychogenic causes—that being stated, it is rare for a person to be experiencing psychogenic pain alone. Too often, we have seen underevaluated patients with chronic pain being diagnosed with psychogenic pain when in fact, there was a clear etiology for their pain that had been overlooked due to suboptimal diagnostic evaluation.
