Low Back Pain in General Practice: Evidence-Based Assessment and Management
From red flag screening to physiotherapy, analgesia, and avoiding unnecessary imaging
Low back pain is the leading cause of disability worldwide and one of the most common presentations in general practice. This guide covers red flag screening, the biopsychosocial model, analgesia ladder, physiotherapy referral, and avoiding the imaging trap.
Clinical Decision Support: This article is for educational purposes and supports — not replaces — clinical judgment. Always verify with current national guidelines, BNF, and specialist consultation when needed.
Low back pain (LBP) is the leading cause of years lived with disability globally and one of the most common reasons for GP consultation. Approximately 80% of people will experience significant LBP at some point in their lives. The vast majority (>90%) have non-specific LBP — no identifiable structural cause — and will recover within 6–12 weeks with appropriate management. The GP's role is to identify the rare serious causes, avoid unnecessary investigations, and facilitate recovery through active management.
Red Flag Screening: What Must Not Be Missed
Cauda equina syndrome is a surgical emergency. Suspect if: bilateral leg weakness/numbness, saddle anaesthesia (perineum/inner thighs), bladder/bowel dysfunction (retention, incontinence). Arrange emergency MRI and same-day surgical referral.
- Cauda equina syndrome: Saddle anaesthesia, bladder/bowel dysfunction, bilateral leg weakness — emergency MRI
- Malignancy: Age >50, history of cancer, unexplained weight loss, pain at rest/night, thoracic pain
- Infection (discitis/osteomyelitis): Fever, IV drug use, immunosuppression, recent spinal procedure
- Fracture: Significant trauma, osteoporosis, prolonged corticosteroid use, age >70
- Inflammatory (ankylosing spondylitis): Age <40, insidious onset, morning stiffness >30 min, improves with exercise, sacroiliac tenderness
The Biopsychosocial Model: Yellow Flags
Psychosocial factors (yellow flags) are stronger predictors of chronicity and disability than physical findings. Identifying yellow flags early allows targeted intervention to prevent transition to chronic LBP.
- Catastrophising: "This pain will never get better", "I must have seriously damaged my back"
- Fear-avoidance behaviour: Avoiding activity for fear of worsening pain
- Low mood, anxiety, or depression
- Poor job satisfaction or work-related stress
- Passive coping strategies (rest, waiting for pain to go away)
- Previous history of chronic pain or multiple unexplained symptoms
NICE NG59: Management Principles
What NICE Recommends
- Reassure: Non-specific LBP is not dangerous; most recover within 6–12 weeks
- Advise to stay active: Bed rest is harmful — it prolongs recovery
- First-line: Supervised group exercise programme (yoga, pilates, aerobic exercise)
- Consider manual therapy (spinal manipulation, mobilisation) as part of a package of care
- Psychological therapy (CBT) for persistent LBP with significant psychosocial factors
What NICE Does NOT Recommend
- Routine X-ray or MRI for non-specific LBP (does not change management; increases medicalisation)
- Paracetamol alone (NICE 2016: no better than placebo for LBP)
- Opioids for chronic non-specific LBP (harms outweigh benefits)
- Bed rest
- Acupuncture (removed from NICE recommendations in 2016 update)
Analgesia: The Practical Approach
| Step | Drug | Notes |
|---|---|---|
| 1 | Topical NSAIDs (diclofenac gel) | First-line for localised LBP; fewer systemic effects |
| 2 | Oral NSAIDs (ibuprofen 400 mg TDS, naproxen 500 mg BD) | Short course (1–2 weeks); use PPI cover; avoid in CKD/CVD/elderly |
| 3 | Weak opioids (codeine 30 mg QDS) | Short-term only; constipation; avoid in chronic LBP |
| 4 | Muscle relaxants (diazepam 2 mg TDS) | Short-term only (max 1 week); dependence risk |
| Adjunct | Amitriptyline 10–25 mg nocte | For neuropathic component (radiculopathy); also improves sleep |
Key Clinical Takeaways
- Screen for red flags at every LBP consultation — cauda equina is a surgical emergency
- Non-specific LBP: reassure, advise to stay active, refer for supervised exercise
- Do not routinely image non-specific LBP — it does not change management
- Identify yellow flags early — psychosocial factors predict chronicity
- Topical NSAIDs first-line; oral NSAIDs short-term; avoid opioids for chronic LBP
- Paracetamol alone is not recommended for LBP (NICE 2016)