A real example: I moved house last weekend, so there are boxes everywhere, and I banged my shin against the edge of the bed. After the obligatory curse, the pain I felt prompted me, almost unconsciously, to look down at it and give it a rub – a brief examination to rule out anything serious. Once my brain was satisfied that I hadn’t done anything serious, and I remembered having done this sort of thing before and it being OK, the pain subsided: there wasn’t any use for it anymore. Next morning my shin sported a bruise, which signified tissue trauma, but again no pain. Since I’ve already satisfied myself that there’s nothing to worry about, my memory of previous experiences guides my expectations that it should settle in a timely fashion.

Alternatively, if I cut myself and not look after it well and it becomes infected, the ongoing pain and throbbing sensation I feel would prompt me to take another look. Since it hadn’t responded in an expected fashion (ie. healing), and seeing that it was red & swollen, the pain might stimulate me to change my behavior & encourage me to do something more appropriate, like use Neosporin or see a doctor.

This more contemporary model can also neatly account for previously harder to explain phenomena like phantom limb pain – the pain someone may continue to experience in an amputated limb after it’s gone. The limb still exists within the sensory homunculus, so anything that stimulates that part of the brain will cause the sufferer to experience pain in that region, even if that region is no longer physically there.

The good news for people in pain is that research demonstrates that merely understanding the mechanisms by which pain is generated by the body can be therapeutic in managing said pain. It can be very reassuring to learn that fluctuations in pain can occur independent of tissue pathology, and this knowledge can allow your pain to be less of a limitation than first thought. Probably the most important thing to do is talk to your physical therapist or medical specialist about pain so that you can understand its causes and influences.

Watch this space for future posts about further aspects about pain – what it is, how it manifests, and what can be done about it when it doesn’t go away.