Key Facts

Chronic pain is a major public health issue and one of the most common reasons for GP consultation. NICE NG193 has significantly changed the approach to chronic primary pain, moving away from pharmacological management towards exercise, psychological therapy, and self-management.

Epidemiology

• Chronic pain: 28 million UK adults (~43%)
• Moderate-severe chronic pain: 14% of adults
• Higher prevalence in women, older adults, lower socioeconomic groups
• Associated with significant disability, mental health comorbidity, and social isolation
• Accounts for 4.6 million GP appointments/year in England

Aetiology

• Chronic primary pain: no identifiable underlying condition; includes fibromyalgia, chronic widespread pain, complex regional pain syndrome (CRPS), chronic pelvic pain, chronic headache, IBS
• Chronic secondary pain: identifiable underlying cause — neuropathic pain (diabetic neuropathy, post-herpetic neuralgia), musculoskeletal (OA, RA), cancer pain, post-surgical

Pathophysiology

• Central sensitisation: amplification of neural signalling within the CNS resulting in pain hypersensitivity
• Peripheral sensitisation: lowered threshold of nociceptors
• Neuroplasticity: structural and functional changes in pain-processing areas (somatosensory cortex, prefrontal cortex, limbic system)
• Descending modulation dysfunction: impaired inhibitory pain pathways
• Psychosocial amplification: fear-avoidance, catastrophising, depression, anxiety, social factors all modulate pain experience
• Chronic primary pain is not 'imagined' — it reflects real neurobiological changes in pain processing

Chronic Primary Pain

• Widespread pain without identifiable tissue damage or pathology
• Often associated with: fatigue, sleep disturbance, cognitive difficulties ('fibro fog'), low mood
• Disproportionate to any identifiable pathology
• Affects function and quality of life significantly

Assessment

• Comprehensive biopsychosocial assessment
• Pain characteristics: location, duration, quality, severity (VAS/NRS), aggravating/relieving factors
• Impact on function: work, sleep, mood, relationships, activities
• Psychological: PHQ-9, GAD-7, catastrophising (PCS)
• Current medications and previous treatments tried
• Medication use: opioid dose, escalation pattern, aberrant behaviour

Red Flags (Exclude Serious Pathology)

• New onset pain in patient >50 years with weight loss (malignancy)
• Neurological deficit (cauda equina, cord compression)
• Bone pain with raised calcium (metastases)
• Night pain/morning stiffness >45 min (inflammatory arthritis)
• Fever with pain (infection)

Bedside

• Pain assessment scales (VAS 0-10, NRS)
• Functional assessment
• PHQ-9, GAD-7 (comorbid depression/anxiety)
• Brief Pain Inventory
• DN4 (Douleur Neuropathique 4): screening for neuropathic pain component

Bloods

• FBC, ESR, CRP (exclude inflammatory/infectious cause)
• TFTs (hypothyroidism can cause myalgia)
• Vitamin D (deficiency common in chronic pain patients)
• HbA1c (diabetic neuropathy)
• Calcium (bony metastases, hyperparathyroidism)

Imaging

• Not routinely indicated for chronic primary pain (may reinforce unhelpful beliefs)
• Targeted imaging for suspected chronic secondary pain (X-ray for OA, MRI for suspected structural pathology)

Special Tests

• Nerve conduction studies/EMG: if neuropathic pain suspected
• DEXA: if osteoporosis suspected
• DN4 questionnaire: ≥4/10 suggests neuropathic component

Chronic Primary Pain (NICE NG193)

• Recommended:
  • Supervised group exercise programme: most effective intervention
  • Psychological therapy: CBT or ACT (acceptance and commitment therapy)
  • Acupuncture: consider a single course
  • Antidepressant for pain: ONLY if also treating comorbid depression/anxiety; NOT for pain alone
  • Pain neuroscience education
  • Self-management support
• NOT recommended (NICE NG193 — for chronic primary pain specifically):
  • Paracetamol, NSAIDs, opioids, gabapentinoids, benzodiazepines, antidepressants (for pain), ketamine, local anaesthetics, corticosteroid injections, TENS

Chronic Secondary Pain — Neuropathic Component (NICE CG173)

• First-line: amitriptyline 10mg ON (titrate to 75mg), duloxetine 60mg OD, gabapentin 300mg TDS (titrate to 1200mg TDS), or pregabalin 75mg BD (titrate to 300mg BD)
• Second-line: switch or combine first-line agents
• Third-line: tramadol (short-term), specialist referral
• Topical: capsaicin 0.075% cream, lidocaine 5% patches (post-herpetic neuralgia)

Opioid Management

• Avoid long-term opioids for chronic non-cancer pain wherever possible
• If already on long-term opioids: discuss dose reduction, agree tapering plan
• Review all patients on opioids: risks (dependence, OIH, falls, endocrine effects), benefits (often diminishing)
• Use opioid risk tools (ORT) before initiating

Referral Criteria

• Multidisciplinary pain clinic: complex chronic pain, failed primary care management, opioid reduction support
• Psychology/IAPT: for CBT/ACT
• Physiotherapy: for supervised exercise
• Addiction services: if problematic opioid/gabapentinoid use

• Chronic primary pain is a long-term condition requiring ongoing self-management
• CBT/ACT: reduces pain-related disability and distress in 40-60%; does not necessarily reduce pain intensity
• Exercise: improves function and pain by 20-30% in most studies
• Opioids: no evidence of long-term benefit beyond 3 months for chronic non-cancer pain; significant risk of harm
• Prognosis is improved by: early intervention, active coping strategies, psychological support, sustained physical activity
• Poor prognostic factors: catastrophising, fear-avoidance, ongoing compensation/litigation, depression, social isolation
• Many patients achieve meaningful improvement in function and quality of life with multimodal management

NICE NG193 vs CG173 — Key Differences

Fibromyalgia — ACR 2016 Revised Diagnostic Criteria

Opioid Concerns in Chronic Pain