Summary

Bryson begins chapter 19 by describing pain as a necessary but unwelcome bewilderment that is one of medical science’s greatest challenges. Pain acts as a protector such as when it saves us from burning our hands on a hot stove, but up to 40 percent of people suffer from chronic pain at some point in their lives. How pain works is still a mystery to medical science. Bryson gives examples of unexplainable pain like phantom limb pain. He writes there is no pain center in the brain and no one place where all the pain signals congregate. Although the brain has no pain receptors, to feel pain our brains must receive a signal.

It is challenging to even define pain or measure it. The most famous measurement of pain is the McGill Pain Questionnaire from 1971, which lists words like stabbing, stinging, dull...