Pain Classification

Pain is a stimuli that is generally meant to alert creatures that experience it to some kind of damage, and in many cases to prod them to take actions that will help them recover from that damage.

So while back pain might be brutal and alarming, it can also signal to the sufferer that they might want to work out their core or spend less of their day sitting in a non-optimal position, and while the sharp pain associated with a sunburn might seem unnecessarily punitive, it can also serve as a reminder to the sufferer that they have burns across their protective epidermis, and may thus want to avoid direct sun exposure for the next several days (and maybe apply some aloe).

Pain that has no obvious explanation—that’s not caused by tissue damage, sprains, broken bones, or the like—is called “nociplastic pain,” and is often associated with chronic issues like fibromyalgia. This type of pain isn’t fully understood, but it’s thought that it might be related to a dysfunction in the sufferer’s pain signaling processing mechanisms, and in some cases might be related to an overabundance of the neurotransmitters that incite pain, immune activity in their peripheral and central nervous systems, and/or the over-sensitization of the portions of their brain that help process pain, emotions, and sensory information.

Nociceptive pain, in contrast, is the kind experienced by people (or other biological entities) that have some sort of tissue damage, be it superficial or deep (the latter of which can be further sub-divided into physical and visceral varieties).

Neuropathic pain is similar in some ways to nociceptive pain, but rather than being triggered by tissue damage, it’s sparked by an issue with the sufferer’s nervous system, and is thus divided into peripheral and central sub-categories, referring to issues with the peripheral nervous system and the brain/spinal cord, respectively.

There are other pain categorizations beyond these three main ones, including distinctions between chronic and acute pain (long-lasting versus temporal), and what we might think of as psychologically-linked pain that can arise from normal, non-damaging stimuli like touch, pressure, and heat or cold, which is called allodynia.

Adjacent to that is hyperalgesia, which is pain that’s triggered by pain-causing stimuli, but which is a wildly out of proportion response to that stimuli. This can be caused by both psychological and physical factors, and is in some cases related to certain drugs, inflammation, or a trained response to those stimuli.

All of which is useful to understand in part because we all experience pain differently, we all experience different types of pain differently, and because pain can significantly impact our mood, our capacity to think and function, our relationships, and even our assumptions and beliefs about life and the future.