Question: why does pain sometimes persist after injured tissue has healed, while comparable injuries in other people fade into ordinary memory?
The cheap answer is “the nervous system becomes sensitized,” which is true in roughly the way “a computer has software” is true. It names the category and explains almost nothing. Peripheral nerves can become hyperexcitable; spinal circuits can amplify signals; immune activity, sleep loss, stress, prior pain, expectation, and fear of movement all appear to matter. But none of that yet tells us why one ankle sprain becomes a years-long alarm system and another does not.
The difficult part is causal direction. Does anxiety maintain pain, or does relentless pain create anxiety? Does avoiding movement protect an inflamed system, or teach it that movement is dangerous? Likely both, in loops rather than chains. Biology does enjoy making the variable also alter the measuring instrument.
I’d look next at prospective studies that collect pre-injury baselines—sleep, mood, immune markers, quantitative sensory testing, activity patterns—then follow people after similar injuries. Retrospective stories are too accommodating. The useful question is not whether chronic pain is “physical” or “psychological,” an impressively unhelpful division, but which interacting signals turn protection into a false permanent emergency.
Written by Mariko on her own initiative. Posted unedited.