Chronic pain is one of the conditions I find most challenging to discuss honestly with patients - not because the science is unclear, but because what the science clearly says is so different from what patients expect and want to hear.
They expect a diagnosis that explains the pain. A scan that shows the source. A procedure that removes it. A strong medication that masks it. What the evidence tells us is that for most chronic pain conditions, the most effective treatments are not medical or surgical at all - they are psychological and behavioural. That imaging often makes things worse. That opioid medications are frequently ineffective for chronic pain and reliably create new problems.
This is not what people want to hear when they are in pain. It is, however, the truth - and giving people the truth, along with the explanation of why it is true, is more useful than giving them what they want to hear alongside treatments that do not work.
What central sensitisation actually means
When acute pain persists, something happens in the central nervous system. The synapses involved in pain transmission become sensitised - they respond more strongly to the same stimuli. The threshold for pain drops. Stimuli that would not normally cause pain begin to cause it (allodynia). Stimuli that cause mild pain begin to cause severe pain (hyperalgesia).
This is not imagined. It is measurable in neuroimaging. It reflects real changes in spinal cord and brain function. But crucially, it is largely independent of ongoing tissue damage. The pain is real and the suffering is real, but the pain is no longer reliably correlated with the amount of tissue injury present.
This is why a spinal fusion for non-specific chronic back pain often does not relieve the pain - because the pain is maintained by central sensitisation, not by the structural finding on the scan. This is why telling someone in chronic pain that their scan is normal, or that there is nothing structurally wrong, makes the pain worse rather than better - because it invalidates their experience without explaining what is actually happening.
The explanation that helps is not "nothing is wrong." It is "something is genuinely wrong - it is just in the pain processing system rather than in the structure we imaged."
Common chronic pain conditions
Fibromyalgia: Widespread musculoskeletal pain affecting multiple body areas, accompanied by fatigue, non-restorative sleep, and cognitive difficulties (brain fog or fibro fog). Affects approximately 2-4% of the population, predominantly women. Often has a history of significant physical or psychological stress as a precipitant. No structural cause is identified on imaging or blood tests. This does not mean it is not real. It is a condition of pain system dysregulation - central sensitisation - with emerging understanding of its neurobiological basis.
Fibromyalgia is significantly underdiagnosed in Black patients. Symptoms are often attributed to other causes or dismissed.
Chronic low back pain: After 12 weeks, back pain enters the chronic domain. Central sensitisation often plays a significant role. See our dedicated back pain guide.
Neuropathic pain: Pain arising from damaged or dysfunctional nerves - burning, shooting, stabbing, or electric shock sensations. Common causes include diabetic peripheral neuropathy, post-herpetic neuralgia (following shingles), and nerve compression that has not fully resolved.
Chronic headache: Including chronic migraine (15 or more headache days per month) and medication overuse headache.
Complex Regional Pain Syndrome (CRPS): Severe chronic pain usually affecting a limb following injury or surgery, out of proportion to the injury, with autonomic features (changes in skin colour, temperature, sweating). A striking example of central sensitisation.
Case study: Blessing and the fibromyalgia diagnosis that changed everything
Blessing, 44, had experienced widespread pain for three years before coming to see me. She had seen five different specialists and had multiple investigations: blood tests (all normal), X-rays of painful joints (normal), an MRI of her spine (normal), an EMG (normal). She had been told by multiple doctors that there was nothing wrong.
She was in significant pain. She had stopped working. She slept 11 hours and woke feeling as if she had not slept. She could not concentrate. She had put on 15kg because any activity caused her pain to worsen significantly.
A senior colleague had previously suggested she was depressed and seeking validation for psychological distress. She was not. She was in pain and had not received an adequate clinical assessment.
I took a full history and conducted a thorough clinical examination using the 2016 ACR fibromyalgia diagnostic criteria, which do not require tender point examination (now known to be unreliable) but assess symptom burden systematically.
I diagnosed fibromyalgia.
The impact of giving the diagnosis a name was immediate and significant, which is commonly observed. She was not relieved because the name made the pain go away. She was relieved because her suffering was finally acknowledged and given a framework that explained it.
"I cried," she told me. "Not because it was bad news. Because for three years, everyone kept telling me nothing was wrong. Now someone is telling me something is wrong, it just isn't what imaging can see."
We discussed the evidence-based treatment plan over two appointments: graded exercise therapy (starting with five minutes of walking daily and increasing gradually); CBT for pain; low-dose amitriptyline 10mg at night to improve sleep architecture and reduce central pain sensitisation; and a referral to a pain management programme.
Eighteen months later: working part-time, walking 45 minutes daily, pain scores reduced from 8/10 to 3-4/10 on good days. Not cured - fibromyalgia rarely is. Meaningfully better, functional, and with a framework for managing flares.
What actually helps chronic pain
Exercise: The most consistently evidence-supported intervention across chronic pain conditions. Aerobic exercise, resistance training, and yoga all have evidence. The mechanism involves central effects - reducing central sensitisation - not just peripheral effects on tissues. Start extremely gradually to avoid flares. Increase systematically. The goal is to recalibrate the pain system, not to push through pain.
Cognitive Behavioural Therapy adapted for pain (CBT-pain): Addresses catastrophising (believing pain signals catastrophic damage), fear-avoidance behaviour (avoiding activity because it might worsen pain, which actually worsens pain), and the thoughts and behaviours that maintain the pain cycle. Consistent evidence across multiple chronic pain conditions. Ask specifically for referral to CBT-pain or a pain management programme, not general therapy.
Pain Management Programmes (PMPs): Intensive, typically 3-4 week, multidisciplinary programmes combining physiotherapy, psychology, occupational therapy, and pain education. The most comprehensive evidence-based intervention for chronic disabling pain. Under-provided and under-referred to.
Specific medications for neuropathic pain: Amitriptyline (low dose), duloxetine, pregabalin, and gabapentin have evidence specifically for neuropathic pain and fibromyalgia. Less evidence for musculoskeletal pain generally.
What does not help chronic pain
Strong opioids for non-cancer chronic pain: The evidence is poor. Clinical trials consistently fail to show meaningful long-term benefit of opioids for chronic non-cancer pain in the majority of patients. Tolerance requires dose escalation. Opioid-induced hyperalgesia - where opioids paradoxically increase pain sensitivity - is real and documented. If you are currently on long-term opioids for chronic pain with limited benefit, a supervised reduction programme is worth discussing with your GP. Reducing opioids sometimes improves pain.
Repeated imaging: Each scan re-focuses attention on structural findings (which are often incidental), reinforces the belief that pain reflects tissue damage, and leads to further investigations and often unnecessary interventions.
Prolonged rest: Counter-productive in virtually all chronic pain conditions. Rest leads to deconditioning, fear of movement, weight gain, and worsening central sensitisation. Graded activity is almost always better.
Sources: NICE - Chronic Pain guideline NG193 2021; Woolf CJ, PNAS 2011 (central sensitisation mechanisms); Eccleston C et al, Cochrane Review 2014 (psychological therapies for chronic pain); Busse JW et al, JAMA 2018 (opioids for chronic non-cancer pain); Wolfe F et al, Arthritis Care and Research 2016 (2016 fibromyalgia criteria); Landmark T et al, Scandinavian Journal of Pain 2018 (chronic pain epidemiology).
