In order to understand the concept of pain and its relationship to the current opioid crisis, it is prudent to review the neurology of pain an why it exists. Several concepts are important to integrate.
Nociception: Nociception is the capacity to sense a potentially tissue damaging (noxious) stimulus. To illustrate this one should place a forefinger in a glass of ice water and determine how long passes until an unpleasant sensation arises. If one performs this experiment in a large group, one can recognize that, although the stimulus is the same (a glass of ice water), the sensation arises at different rates in different people.
In fact, a bell shaped curve will describe the distribution in any population of people. Within 30 seconds almost all will have perceived an unpleasant sensation that is known at pain. Nociception is a very primitive sensation.
It is present in virtually all animals, even those without a brain, such as Aplysia, the sea slug. Though it lacks a brain, it has nerves and ganglia that allow it to sense and move away from a noxious stimulus. Nociception is absolutely essential to our survival and well-being. Without it, one would suffer tissue damage and ultimately death. The human disease, leprosy, is a salient example of an infection that destroys the nerves that are responsible for nociception. That lack of nociception is what causes all of the disfigurement that is characteristic of leprosy. Anyone who has had a dental anesthetic is aware that one can inadvertently bite one’s own lip until the anesthetic wears off.
When my father died 3 years ago, my comments at his funeral noted that the greatest aspiration any of us can have is to make a difference in the world. My father’s life made a difference.
Nearly every morning lately, as I make my daily dart to the metro station two blocks away, I pass a familiar face. She is one of about a dozen women who toil in the local nail salon. She does not live in my neighborhood, yet I see her early most mornings hiking up our hill, long before the salon opens.