53, I've read that some drugs cause hypersensitivity to pain. Opioid-induced hyperalgesia is one term for what happens to those on long term opiods. I believe it! I have a friend on O for pain, and when she breaks a nail short she emits a blood-curdling scream, followed by outright writhing in pain for an hour or so. It hurts me to see that, because it's as real as anything.
Causes. Hyperalgesia is induced by platelet-activating factor (PAF) which comes about in an inflammatory or an allergic response. This seems to occur via immune cells interacting with the peripheral nervous system and releasing pain-producing chemicals (cytokines and chemokines). https://en.wikipedia.org/wiki/Hyperalgesia
Reading up on it, Platypus Venom is know for this. Too weird.
I have my own set of issues, but strangely enough, pain is not one of them. I generally don't hurt at all,,,, yet. However, I've injured myself enough times to know just how much I hate pain.