The ouch part of pain begins when something—heat, certain chemicals or a mechanical force—activates special nerve endings called nociceptors. Once they are activated, they trigger a cascade of events with a representation of that signal going through your nerves and into your spinal cord and then to the brain. And that’s when things get really complex.
Pain signals interact with many different brain areas, including those involved in physical sensation, thinking and emotion. That leads to all the complexities of what we feel associated that initial hurt.
Having an emotional component linked to the sensory experience is a great memory enhancer. If you touch a hot stove your brain remembers, and you will never do that again.
The link between pain and emotion is a good thing, but sometimes it can also be destructive. Mental health disorders amplify pain. They engage regions of the brain that associate with pain processing, and they can also facilitate rumination and fearful focus on the pain. And when pain doesn’t go away it can cause disabling changes in the brain. Pain is a danger signal, but once pain becomes chronic these pain signals no longer serve a useful purpose. Over time, these signals can lead to problems like depression, anxiety and stress, but it’s often possible to break that cycle by learning techniques that help pain patients gain some control of the way their brains are processing pain signals. For example, a state of relaxation is an antidote to the hard-wired pain responses that are automatically triggered by the experience of pain.
For some patient techniques like these can provide an alternative to pain drugs, including opioids. And for pain patients who rely on medications, psychological therapies can often help the drugs work better.