Chronic Pain and the Brain
If you experience chronic pain, understanding it can help you to manage the pain and aid your recovery, so in this post I am going to explain how pain is associated with more than just biological factors, such physical damage, disease or abnormalities, but also by psychological and socio-economic factors. I will also talk about the brain's role in pain and our sensitivity to it.
The Biopsychosocial Model of Pain
It was George L Engel who first postulated in
the 1970s that human health was affected by an interplay of biology, psychology
and socio-economics, which is known as the biopsychosocial model. This is in keeping
with traditional holistic practices, which work on the body and the mind. This post is about chronic pain, so
I will focus on the biopsychosocial influences on that here:
Biological
The biomedical model of pain sees biological factors as the root cause of pain, whereas the biopsychosocial model sees them as just one aspect of the pain experience. Examples of biological effects on pain are soft tissue damage (sprains and strains), joint problems (dislocations, osteoarthritis), diseases (rheumatoid arthritis) and herniated discs.
Psychological
Emotions play a key role in the pain experience, with negative emotions such as fear, anger, distress and depression increasing the level of pain experienced. We can be prone to thinking the worst when we are in pain (‘This going to affect my ability to work’, ‘It is going to feel like this forever’ etc), which is not helpful to recovery. This is known as catastrophising.
Socio-economic
The most vulnerable and deprived in
society are the most prone to chronic pain for various reasons, including: a
lack of control over their circumstances, a lack of financial resources to deal
with the cause of the problem and higher than average levels of stress.
The biopsychosocial model helps to explain why a significant number of people who have a bulging disc, a rotator cuff tear in their shoulder or a meniscal tear in the knee experience no pain or discomfort, whereas others with no identifiable physical damage to their body can experience debilitating pain.
Pain and the Brain
We have sensory receptors in our tissues, which are known as nociceptors, that send a warning signal to the brain if they detect a potentially harmful stimulant, such as pressure, injury, heat or cold. It is just a warning shot, not pain itself. It is the central nervous system that decides what to do with the message. It can decide to ignore quite severe damage or to react to a harmless sensation. For example, one experiment found that participants with irritable bowel syndrome felt pain when air was fed into their intestines whereas those without the condition experienced only mild discomfort (akin to trapped wind): same physical effect on the tissues, different pain response from the central nervous system.
Sensitisation
It is normal for injured tissue to be hypersensitive to pain in order to protect it from further damage. This is known as peripheral sensitivity. Most injuries heal within six weeks and peripheral sensitivity subsides. What can then happen is that the central nervous system distorts signals coming from the previously injured area causing significant pain to persist for months or years, which is known as central sensitisation. The pain experienced in chronic conditions such as fibromyalgia, osteoarthritis, headaches and low back pain are believed to be due to central sensitisation. The central nervous system has got so used to sending the pain signal that it has worn a well-trodden path of pain and is stuck in the rut.
This does not mean that such pain is just in your head. It is a very real experience. It is telling you something about your life, and the good news is that there is action that you can take to gain control over the pain. That usually entails working on the four pillars of health: relaxation, sleep, nutrition and exercise (I plan to talk more about these in my next post). Cognitive behavioural therapy and psychotherapy can also be helpful in some cases of chronic pain.
Massage and reflexology promote relaxation of body and mind, so can be beneficial in the management of chronic pain. Tai chi and qigong can also help through gentle exercise and the meditative nature of the practices. The Articles & Research page of my website includes links to research on all this.
Do get in touch if you would like to book an appointment or join a class. And if you would like to find out more about chronic pain, I can recommend Elliot Krane’s TED Talk ‘The Mystery of Chronic pain’.
