(Original blog posted on More Good Days and written by Mandy Mercuri, PhD Science, Lived Experience Pain Advocate and My Health Story Advisory Member)
Do you have chronic pain? Then this article is for you, even if you have been recently diagnosed or have been living with pain for many years. We’re going to unpack this beast and explain the main causes, types, symptoms, ways it can be diagnosed and available treatments.
What is pain?
It’s that unpleasant sense that you feel somewhere (and sometimes everywhere) in your body that you probably know TOO well. So we will look at the purpose of pain to answer this question.
Simply put, pain is our internal alarm system that helps us avoid and respond to potentially dangerous situations. When you register pain after placing your hand on a hot stove, that’s the brain’s way of persuading you to withdraw. And, of course you do usually by getting your hand out of there – quick smart. Our bodies have special danger detectors – called nociceptors – that can detect something potentially harmful (extreme heat in this case) and the message gets passed into the central nervous system (spinal cord and brain) for processing.
Processing is a broad term for the way information bounces around the brain being analysed and interpreted. In this processing, it’s the central nervous system’s job (subconsciously, and without your awareness) to decide whether the body needs protecting. If the answer is yes, pain will likely follow. This is a normal reaction that protects us from any further harm. However, chronic or persistent pain can occur when this process changes and the nervous system becomes sensitised. The messages start firing all the time, often without any actual danger and the pain just keeps happening.
What causes chronic pain?
Pain is considered chronic or persistent when it has lasted longer than three months (as opposed to acute pain). Chronic pain is complex. If it wasn’t, it probably wouldn’t have lasted so long, and it can have a range of causes.
It can also be triggered by a range of different initial events, including:
Physical Trauma (injuries/surgeries)
If you sprain your ankle or cut your finger, healing will occur. It’s an unstoppable process. But sometimes, even though healing has occurred, pain persists. When I went in for spinal surgery at age 11, I had no idea I would be living with chronic back pain all these years later. I know now my pain isn’t because my back is still damaged, but because my nervous system responded in a way that amplified signals from my back. We now call this nociplastic pain (see this article to understand the different types of pain).
Illness
Persistent pain also sometimes comes on following an illness such as a virus. This is likely because illnesses trigger reactions in our immune and nervous systems, and after the illness has subsided, our immune and nervous systems might still remain in a state that makes us more sensitive.
Nerve injury
Nerves can be damaged in a range of ways from injury, compression, accidents, illness, disease and drug misuse. Normally, only nerve endings can trigger nerve impulses and the length of the nerve is simply a cable that transmits that message from point A to point B. But a nerve injury can result in impulses starting at parts of the nerve that normally only conduct messages. This also explains why you might feel pain in the foot when there is a nerve injury in the lower back. That is, the brain assumes the messages came from the nerve endings (in the foot) when in fact they started along the nerve (in the lower back).
Psychological trauma
Another common trigger of persistent pain is psychological trauma, such as that related to a sexual assault or other stressful life event. This is likely because of the reaction of our stress systems, and the impact this has on body systems that influence pain (see our Allostasis blog here) and our blog about psychological trauma and pain.
