Pain is an experience, not a radiological finding. The absence of an identifiable structural abnormality does not establish the absence of pain. NICE recognises chronic primary pain as pain for which no underlying condition adequately accounts for the pain or its impact, or where the presentation appears out of proportion to observable injury or disease. Chronic primary and chronic secondary pain may also coexist.
That is a useful starting point, but it is not the end of the analysis. The expert’s task is not to choose between belief and disbelief. It is to decide whether the history, records, clinical findings and course support a coherent medical opinion.
A normal scan answers only a limited question.
Imaging is often treated as though it provides a final verdict. It does not. A normal MRI may reduce the likelihood of certain structural explanations, but it does not measure pain intensity, functional restriction or the effect of symptoms on sleep, mood and activity. Equally, minor degenerative findings do not necessarily explain substantial disability.
The significance of an investigation depends on what condition was being considered, when it was performed and whether the result fits the clinical presentation. A report should therefore avoid the empty phrase “the scan was normal” without explaining what that result does and does not exclude.
The same applies to physical examination. Full power, normal reflexes and unrestricted passive movement may weaken a proposed neurological or mechanical explanation. They do not, by themselves, prove that the claimant has no pain. The report must identify the proper inference rather than pushing the evidence further than it can bear.
Objective evidence is wider than imaging.
In medico-legal work, “objective abnormality” is sometimes used too narrowly. Imaging and examination findings matter, but the wider evidence may include presentation over time, treatment sought, medication use, physiotherapy attendance, occupational consequences and observations recorded by independent clinicians.
None of these matters is conclusive. Frequent attendance can occur for many reasons. Failure to attend treatment may reflect disengagement, practical difficulty, fear of movement or a belief that treatment will not help. Medication may be poorly tolerated or inconsistently used. The point is not to convert background facts into proof. It is to assess whether the overall pattern is medically coherent.
A persuasive report also separates the existence of pain from the extent of disability attributed to it. A person may experience genuine persistent pain while showing greater restriction than the clinical evidence would ordinarily predict. Pain, coping style, fear, low mood, deconditioning, sleep disturbance, work circumstances and social stress may influence function without making the symptoms invented.
Do not use mechanism as a shortcut.
The language of altered pain processing has helped clinicians explain why pain may persist after tissues have healed. The International Association for the Study of Pain describes dysfunctional pain as pain arising from pain receptors, where there is no clear evidence of tissue damage activating peripheral nociceptors, or disease or lesion of the somatosensory system, sufficient to explain it.
The concept is useful, but it can be misused. “Central sensitisation” should not become a phrase inserted whenever investigations are unrevealing. It is not a substitute for differential diagnosis, nor does it automatically establish that an accident caused a prolonged pain disorder. The expert should explain the clinical features supporting the proposed mechanism and acknowledge where the evidence remains limited.
I am cautious when a mechanistic label appears late in the history, particularly if earlier records show little evidence of widespread sensitivity, disproportionate pain behaviour or progressive functional decline. That does not invalidate the diagnosis. It means the reasoning must be shown rather than assumed.
Causation still requires a timeline.
A claimant may have chronic pain without objective abnormality and yet the evidence may not establish that the index event caused the current presentation. The question is not simply whether the pain exists. It is whether the event materially contributed to its onset, persistence or worsening.
The chronology matters. The expert should consider the nature of the original injury, the early symptom pattern, any symptom-free interval, progression of complaints, prior pain conditions, later accidents, psychological difficulties and intervening medical events. The longer the interval between a minor injury and a complex chronic presentation, the more carefully the causal chain must be explained.
“The symptoms began after the accident” is not the same as “the symptoms were caused by the accident”. Temporal sequence is relevant evidence, but it is not a complete causal analysis.
Consistency should be examined, not declared.
Reports sometimes state that a claimant was “consistent” without explaining the comparison being made. Consistency should be assessed across the account given at examination, contemporaneous records, reported activities, employment history, treatment history and observed function. Minor variation is expected. Pain fluctuates, memory is imperfect and medical notes are not transcripts. The expert should not treat every discrepancy as evidence of dishonesty. Material differences, however, require discussion.
Where the evidence does not permit a firm conclusion, the correct response is not to fill the gap with confidence. The expert may state that the symptoms are medically plausible, that no structural explanation has been identified, and that the extent of accident-related disability cannot be determined with precision. Properly expressed uncertainty is part of the opinion.
Prognosis is about function as well as pain.
The absence of objective abnormality does not make prognosis easy. In some cases, it makes prognosis more uncertain. Recovery may depend less on tissue healing and more on activity, confidence, sleep, mood, work circumstances, treatment engagement and effective self-management.
NICE recommends a person-centred assessment of how chronic pain affects life and how life affects pain. That approach is equally sensible in medico-legal assessment. Prognosis should address function, not merely symptom extinction. A claimant may continue to report pain while improving substantially in mobility, work tolerance and independence. The expert should avoid promising recovery simply because investigations are normal. Equally, indefinite symptoms should not be accepted merely because pain has already persisted for a long period. The opinion should identify factors favouring improvement, factors likely to delay it and the limits of the available evidence.
Chronic pain without objective abnormality is not a contradiction. It is also not a diagnosis that excuses loose reasoning. A proper report should make clear what has been excluded, what remains possible, whether the presentation fits a recognised chronic pain pattern, how function has changed, and whether the index event provides a medically persuasive explanation. It should distinguish pain from pathology, symptoms from disability, and chronology from causation.
The strongest opinion is rarely the most absolute one. It accepts the reality of pain as a human experience while remaining disciplined about diagnosis, causation and prognosis. That balance is not evasive. It is the work.
