Understanding Chronic Pain: Why It Persists and How to Manage It
The Complexity of Pain
Pain is complex to explain. Acute pain is a response to a noxious stimulus. It serves to protect the body part from further damage. Chronic pain, however, is often described as pain that persists for six months or longer. At that point, it is usually no longer a useful protective mechanism but becomes a malfunction of the nervous system.
A simple understanding of pain is useful to all of us. Our body has a vast number of nerve receptors that respond to stimuli. Certain receptors respond to sharp, painful stimuli, some to pressure, some to light touch, some to temperature, and some to chemical irritants. The nerve receptor converts that physical or chemical stimulus into an electrical signal that is transmitted to the spinal cord and then to higher centres in the brain. In the head and neck, these responses are usually transmitted directly to specific centres in the brain stem before being sent to the higher brain centres.
How the Brain Interprets Pain
It is in the brain where the interpretation of that stimulus occurs. The brain then sends a response to the body to take action to avoid further damage from what is causing the stimulus. For many stimuli that the brain perceives as being of little threat, a descending inhibitory signal is sent to limit both the pain perception and the body’s protective reaction.
This explains why we can often sleep in uncomfortable positions when we are very tired. Although we might expect discomfort, the descending inhibitory pathways override the feeling of discomfort, allowing us to fall asleep. Similarly, soldiers may not feel pain from a severe injury during the heat of battle, yet the pain becomes very severe once the life-threatening situation has passed. Their descending pathways allow them to continue the fight-or-flight response, but once the threat is gone, the normal pain response kicks in.
Pain Is a Response Within the Brain
It is important to understand that pain is a response within the brain, not at the site that is being stimulated. This is evident when no pain is felt during surgery due to the use of local or general anaesthetic. Our nervous system exhibits neuroplasticity—a mechanism responsible for learning and memory, among other things. However, when a pain response continues for a long period, the initial noxious stimulus and the damage caused by it have often long passed, yet the pain persists. This is common in chronic pain conditions.
The Role of Hypersensitivity in Chronic Pain
At this point, the pain perception is no longer serving a protective role, and the nervous system is malfunctioning. The sensory nervous system, responsible for sending stimuli to the brain, becomes hypersensitive. This can be likened to a smoke alarm near a kitchen that goes off as soon as a little bit of smoke comes from the toaster or stove. In our bodies, this hypersensitivity results in pain that is not reflective of the actual stimulus or causes severe pain from a stimulus that would typically cause only minor discomfort.
These conditions are described as allodynia and hyperalgesia. The general hypersensitivity of the nervous system is called peripheral and/or central sensitisation. In these conditions, the descending inhibitory signals from the brain are suppressed, and the pain experience may be greatly amplified. Other closely related pain receptors around the injury site become activated even though they are not directly stimulated, and the signals sent to the brain become magnified. Additionally, sensory receptors that do not normally send pain signals can change to be perceived as pain. Even within the brain stem, pain signals are amplified.
Referred Pain and Multiple Pain Sites
Previous pain experiences from other parts of the body—often distant from the site of perceived current pain—may have sensory nerve fibres running in close proximity to those from the current body part. These areas become sensitised and start contributing to the overall pain condition, often as referred pain. This is why chronic pain often occurs at multiple sites simultaneously. People with chronic pain commonly experience lower back pain, chronic migraines and headaches, temporomandibular joint (TMJ) pain, neck pain, fibromyalgia, irritable bowel syndrome, pelvic pain, and other types of pain. These hypersensitisation reactions continue in chronic pain and are reflections of how neuroplasticity works within our nervous systems.
The Psychosocial Element of Chronic Pain
The nervous system can unlearn chronic pain responses with the right support and care. Managing chronic pain is complex because it requires more than just preventing further injury, relieving pain, and promoting healing. Chronic pain is described as a biopsychosocial condition, and any treatment that does not address the psychosocial element is unlikely to succeed.
People with chronic pain often seek help from numerous practitioners and specialists without understanding why nothing seems to work. They may feel that medical professionals regard them as hypochondriacs or malingerers. Feeling ignored or misunderstood can lead to hopelessness and depression. Socially, they may withdraw from family and friends, and their work performance may suffer. In severe cases, they may leave work or be terminated. Depression, anxiety, and a constant sense of despair become common, highlighting the importance of addressing the psychosocial element of chronic pain.
Seeking the Right Support
Recognising the need for psychological care is essential. Finding a general practitioner who listens and can place you on a Medicare Mental Health Plan is often the first step. This plan allows individuals to receive multiple subsidised visits to a psychologist, who can use cognitive behavioural therapy (CBT) or other psychological techniques to help unlearn the chronic pain response. Recovery takes time, but finding the right psychologist and committing to the process, even if it takes many sessions, is essential to restoring normality.
Those living in large cities often have access to dedicated pain clinics that provide multidisciplinary management of chronic pain cases. However, those in regional areas may need to rely on their doctor, psychologist, and the support of family and friends to help them on the journey back to a healthy mind and body.
