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This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
Key points
- Non-specific low back pain is the most common cause (~90%) — no identifiable structural or pathological cause
- Screen for RED FLAGS at every presentation: cauda equina, cancer, infection, fracture, inflammatory back pain
- Imaging NOT routinely indicated — X-ray and MRI do not change management in non-specific back pain and can cause harm (incidental findings, medicalisation)
- Management: self-management advice (stay active, avoid bed rest), exercise therapy, psychological support if needed
- NICE NG59: do NOT offer opioids for chronic low back pain. Do NOT offer imaging without red flags
Overview
Non-specific low back pain (NSLBP) is pain in the lumbosacral region without an identifiable specific cause (such as fracture, infection, cancer, cauda equina, or inflammatory spondyloarthritis). It is the most common cause of back pain and the leading cause of disability worldwide. In most cases, the exact anatomical source cannot be reliably identified. Prognosis is generally good — most episodes resolve within 6–12 weeks — but recurrence is common and a proportion develop chronic pain (>12 weeks). Risk factors for chronicity include psychosocial factors (fear-avoidance behaviour, catastrophising, depression, work dissatisfaction).
Epidemiology
Low back pain affects approximately 80% of people at some point in their life. It is the most common musculoskeletal reason for GP consultation and the leading cause of years lived with disability globally. Peak prevalence is age 35–55. Risk factors include sedentary lifestyle, obesity, occupational factors (heavy lifting, vibration), smoking, psychological stress, and previous back pain episodes.
Clinical Features
Symptoms
Pain in the lumbosacral region — may radiate to buttocks or posterior thighs (referred pain, not radiculopathy)
Mechanical pattern: related to movement and posture, variable throughout the day
Morning stiffness <30 minutes (contrast: inflammatory back pain >30 min)
Worse with activity, better with rest (contrast: inflammatory — worse at rest, better with activity)
RED FLAG symptoms: saddle anaesthesia, bladder/bowel dysfunction, bilateral leg weakness (cauda equina)
RED FLAGS: unexplained weight loss, night pain, constant progressive pain, fever, history of cancer
RED FLAG: onset <20 or >55 years with new severe back pain
Signs
Normal neurological examination (intact reflexes, power, sensation)
Paravertebral muscle tenderness and spasm
Reduced range of lumbar movement
Focal neurology (weakness, sensory loss, reflex changes) = suggests disc prolapse or other specific cause
Investigations
First-line
NO routine investigationsNICE NG59: do NOT offer imaging for non-specific low back pain without red flags. Imaging does not change management and may cause harm (anxiety, overtreatment of incidental findings)
Second-line
MRI lumbar spineOnly if red flags present: suspected cauda equina (EMERGENCY), cancer, infection, fracture. Or if considering referral for spinal surgery (after failed conservative management for sciatica >6 weeks)
BloodsOnly if red flags suggest infection (CRP, ESR, FBC), cancer (PSA, myeloma screen), or inflammatory disease (CRP, HLA-B27)
Specialist
X-ray lumbar spineOnly if suspecting fracture (osteoporotic, traumatic) or spondyloarthropathy. NOT for non-specific back pain
1
Self-management (first-line)
- Encourage staying active and returning to normal activities as soon as possible — bed rest WORSENS outcomes
- Reassurance: most back pain improves within 6–12 weeks
- Advise against prolonged rest, heavy lifting, and pain-contingent behaviour
- Self-management resources and education
2
Non-pharmacological
- Exercise therapy: group or individual — stretching, strengthening, aerobic (pilates, yoga, walking)
- Psychological therapies (CBT): if significant psychosocial barriers to recovery
- Combined physical and psychological programme (multidisciplinary rehab): for chronic back pain
- Consider manual therapy (spinal manipulation/mobilisation) as part of a package with exercise — not as standalone
3
Pharmacological (NICE NG59)
- Oral NSAIDs: lowest effective dose, shortest time, with PPI if needed
- Do NOT offer paracetamol alone for low back pain (NICE — no evidence of benefit)
- Do NOT offer opioids for chronic low back pain (NICE NG59)
- Do NOT routinely offer gabapentinoids for non-specific low back pain
- Do NOT offer antidepressants for pain relief in non-specific LBP (NICE)
4
Referral
- Refer for specialist assessment if: red flag symptoms (emergency for cauda equina), persistent symptoms despite conservative management, progressive neurological deficit
- Consider referral for spinal decompression surgery for sciatica (not non-specific back pain) if >6 weeks conservative treatment has failed
Complications
- Chronic pain: ~10–40% develop chronic LBP (>12 weeks). Psychosocial yellow flags predict chronicity
- Disability and work absence: Leading cause of work-related disability
- Depression and anxiety: Commonly coexist — screen and manage
- Iatrogenic harm: Unnecessary imaging, surgery, opioid prescribing — all can worsen outcomes
- Deconditioning: From bed rest and activity avoidance — perpetuates pain cycle
UKMLA Exam Tips
- 1RED FLAGS for back pain: cauda equina symptoms, cancer (weight loss, night pain, >55y new onset), infection (fever, IVDU), fracture (steroids, osteoporosis), inflammatory (age <40, morning stiffness >30 min)
- 2No imaging for non-specific LBP without red flags (NICE NG59) — this is a key guideline point
- 3Do NOT offer opioids for chronic LBP (NICE). Do NOT offer paracetamol alone
- 4Stay active = best advice. Bed rest = harmful
- 5Yellow flags (psychosocial): fear-avoidance, catastrophising, depression, work dissatisfaction — predict chronicity
- 6Inflammatory vs mechanical: inflammatory = young (<40), gradual, better with exercise, worse at rest, morning stiffness >30 min. Mechanical = any age, activity-related, better with rest
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