I've been learning a lot about the role of the brain and the central nervous system in our experience of pain. One of the people who studies this and writes about it is Lorimer Moseley, co-author of Explain Pain. His TED Talk explains, in 15 minutes, some important discoveries in pain research.
As Moseley explains, pain is a sensation created by the brain to protect us. If the brain perceives threat, it may create pain when there is, in fact, no threat. Conversely, there may be great threat but if the brain does not perceive this, we may feel little or no pain.
For those who would like to understand how pain works in greater detail, the following video of a 45 minute lecture will explain more about the neurobiology of pain. Of particular note is his description of "central sensitization" beginning at about the 35 minute mark. What pain research scientists have learned is that the more the nervous system is subjected to pain, the more sensitized it becomes and the less stimulus it requires to feel pain. This underlines the importance of treating pain promptly rather than waiting, often for years, to treat it. It also illustrates why therapy for pain should not be painful. "No pain, no gain," is not a good motto when it comes to treating pain!
I hope you find these videos interesting and informative. Understanding how pain works may not immediately stop the hurt, but it can help to change the experience and start us down the path of reducing or eliminating pain.