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Back pain red flags
Most back pain is mechanical — your job is to find the few that aren't. Screen every patient for the serious causes (cauda equina, cord compression, infection, fracture, aortic aneurysm), then manage non-specific back pain well: reassurance, activity, sensible analgesia and no unnecessary imaging. Built for revision, not live patient decisions.
Settle them, and check the basics
red flags firstRed flags — what each should make you think
In an older patient with sudden "renal colic" or back pain, think aortic aneurysm first, especially if they're pale, sweaty or hypotensive. A bedside ultrasound of the aorta takes two minutes.
First actions
- 🚩Screen for red flags
- 🦵Neuro exam
- 🫀Abdomen + pulses
- 🌡Temperature
- 💊Analgesia
- MRIImage only if it changes management
Understand the patient
serious vs non-specificNon-specific (mechanical) back pain — NICE NG59
- Reassure: most improve within weeks
- Stay active, continue normal activities as far as possible
- Oral NSAIDs (lowest dose, shortest time, with gastroprotection if needed) — weak opioids only if NSAIDs unsuitable, short-term
- Don't offer paracetamol alone, gabapentinoids or antidepressants for low back pain
- Don't image routinely
- Risk-stratify (e.g. STarT Back) and refer to physiotherapy/exercise programmes
Sciatica
- Leg pain worse than back pain, dermatomal
- Usually settles within 6–12 weeks
- Check for bilateral symptoms and CES red flags
- Urgent referral for progressive motor deficit
Work A–E — assess and act as you go
The diagnoses you must not miss
tap to open eachWhat points toward it, what would rule it in, and how to manage it.
Bilateral sciatica, saddle anaesthesia, urinary or bowel dysfunction.
Emergency MRI.
Spinal surgery. See the cauda equina page.
Known cancer (breast, lung, prostate, kidney, myeloma), thoracic/band-like pain, progressive neurology.
MRI whole spine.
See the spinal cord compression page.
Fever, IVDU, immunosuppression, recent procedure, UTI/bacteraemia; constant pain, tenderness.
MRI with contrast, CRP/ESR, blood cultures.
Antibiotics (after cultures if stable), spinal surgery if neuro deficit or abscess.
Over 50, sudden back/abdominal/flank pain, pulsatile mass, hypotension, collapse.
Bedside USS, CT angiogram if stable.
Vascular emergency — permissive hypotension, MHP.
Trauma, osteoporosis, long-term steroids, older age; point tenderness.
X-ray / CT; MRI if neuro signs.
Analgesia, spinal referral if unstable or neuro deficit; bone health.
Investigate — what to order, when, and what it tells you
test with a question in mindNo imaging
MRI
Bloods
Bedside USS
How the plan comes together
disposition · handoverhome
Non-specific back pain or sciatica without red flags: analgesia, stay active, physio, CES safety-netting card.
admit / urgent
Any red flag requiring imaging or treatment, uncontrolled pain, or unable to mobilise safely.
Hand over: red flags asked, neuro exam, imaging requested.
Screen every patient for the serious causes, image only when it changes management, and send the rest home with good advice and a CES warning card. Nicely done getting here.
Clerking template
copy or downloadBack pain red flags — documentation structure
A structure and prompt list to help you document and think systematically. It is not a completeness check and cannot guarantee nothing is missed — use your trust's own proforma, your seniors, and your clinical judgement.
Test yourself
active recallCover the answer, say it out loud, then reveal. Retrieval beats re-reading.
0 / 12 knownFrequently asked questions
quick answersWhat are the red flags for back pain?
- Saddle numbness, bladder/bowel change — think cauda equina
- Known cancer, thoracic pain, progressive neuro — think metastatic cord compression
- Fever, IVDU, immunosuppressed — think discitis / epidural abscess
- Trauma, osteoporosis, steroids — think vertebral fracture
- Over 50, sudden pain, pulsatile mass, shock — think ruptured AAA
- Night pain, weight loss — think malignancy
- Under 40, morning stiffness over 30 min, better with exercise — think axial spondyloarthritis
What is the initial management of back pain?
- Screen for red flags — every patient — CES, cancer, infection, fracture, AAA
- Neuro exam — lower limbs + saddle sensation if any neuro symptoms
- Abdomen + pulses — AAA, pyelonephritis, pancreatitis
- Temperature — infection
- Analgesia — NSAID (if safe) first-line for non-specific pain
- Image only if it changes management — red flags or planned intervention
Always alongside senior support and your local guideline.
What diagnoses must you not miss in back pain?
- Cauda equina syndrome — saddle · bladder
- Metastatic spinal cord compression — cancer + back pain
- Spinal infection — fever · IVDU
- Ruptured / leaking AAA — older · shock
- Vertebral fracture — trauma · osteoporosis
Open each one in the must-not-miss section for what points toward it, how to rule it in, and how to manage it.
What investigations should a junior doctor order for back pain?
- No imaging — Non-specific back pain without red flags.
- MRI — Red flags (emergency for CES/MSCC), or if considering intervention.
- Bloods — FBC, CRP, ESR, calcium, PSA, myeloma screen, cultures.
- Bedside USS — Older patient with acute pain — check the aorta.
Admit or discharge: how is the plan decided for back pain?
- Home — Non-specific back pain or sciatica without red flags: analgesia, stay active, physio, CES safety-netting card.
- Admit / urgent — Any red flag requiring imaging or treatment, uncontrolled pain, or unable to mobilise safely.
Is there a clerking template for back pain?
Yes — there is a free clerking template for back pain on this page, structured as presenting complaint, red flags asked, history, examination (A–E), investigations, differentials, plan and escalation. You can copy it or download it as a Word document. Jump to the template.
Keep going
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Sorting the benign from the serious.