Health condition · Clinically reviewed
Sciatica, radicular leg pain — natural history and stepwise treatment.
Pain radiating from lower back through the buttock and down the leg — usually from a lumbar nerve root. Most improve without surgery; imaging is not automatic.
Why trust this guide
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Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
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Sourced from guidance
Every claim is checked against NICE, RCP or peer-reviewed sources you can see at the end.
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Current for 2026
Reflects current UK guidance on stepwise assessment, imaging, injections and spinal surgery.
Key facts
Sciatica at a glance.
The essentials, in plain English — what sciatica is, when imaging matters, and how the stepwise plan is built.
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Definition
Leg pain in a lumbar nerve-root distribution — usually radiating from the lower back through the buttock and down the leg.
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Common levels
L4, L5 and S1 are the levels most often involved — each produces a recognisable pattern of pain, numbness and weakness.
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Natural history
Most episodes improve within 6–12 weeks without surgery — a stepwise plan gives the nerve room to settle.
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Imaging
MRI is NOT first-line — it is reserved for red flags, or for pain that persists beyond 6 weeks despite treatment.
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Injections
Epidural steroid injections may help specific patients — targeted, time-limited, and used alongside rehab.
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Surgery
Reserved for select structural indications — persistent radiculopathy, progressive weakness, or neurological compromise.
Why this guide matters
Stepwise decisions beat scattergun tests.
Sciatica is common; most people get better without an MRI or a surgeon. The value is in doing the right thing at the right time.
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Screen for red flags first
A short set of questions rules out serious causes — cauda equina, infection, cancer and fracture.
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Time heals most sciatica
Most episodes settle in 6–12 weeks with medication, graded activity and physiotherapy — no imaging required.
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Procedures fit specific patterns
Injections and surgery help a subset of patients — chosen carefully, they can be transformative.
How the diagnosis is made
From first assessment to a stepwise plan.
The steps a UK clinician will normally follow, in order — so you know what to expect and why imaging is not always the first move.
Phase 1 · Screening
Red flags, neurological exam and straight leg raise
Phase 2 · Assessment
Watchful waiting and imaging if indicated
Phase 3 · Managing
MDT pain, injections, surgery if needed
- 01
Screening
Red-flag screen
Cauda equina questions at every visit — saddle numbness, urinary retention, bilateral leg weakness or progressive deficit.
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Screening
Neurological examination
Power, sensation and reflexes across L4, L5 and S1 — to localise the affected nerve root.
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Screening
Straight leg raise
A positive test reproduces the radicular pain — a useful bedside indicator of nerve-root irritation.
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Assessment
Watchful waiting with medication
A 6-week period of simple analgesia, neuropathic-pain medication and graded activity — most people improve.
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Assessment
MRI if persistent or red flags
Imaging is reserved for pain persisting beyond 6 weeks, or when red flags or progressive neurology appear.
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Managing
MDT pain assessment
Multidisciplinary review — pain physician, physiotherapist and psychologist together, when pain is complex.
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Managing
Spinal surgery consultation
For select cases — persistent radiculopathy from a structural cause, or progressive neurological compromise.
Typical timeline: 6–12 weeks from first appointment to settled leg pain.
Symptoms
What sciatica looks like.
The pattern matters more than any single symptom — where the pain travels, what it does with movement, and whether there is numbness or weakness.
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Leg pain greater than back pain
The classic sciatica pattern — the leg pain dominates, even if the back is uncomfortable too.
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Radiating below the knee
Pain travels past the knee into the calf, foot or toes — following a nerve-root distribution.
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Pins and needles
Tingling or altered sensation in a dermatome — often in the calf, foot or outer leg.
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Focal weakness
A specific muscle group is weaker than expected — foot drop, calf weakness or difficulty rising on tiptoes.
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Worse with prolonged sitting
Sitting for long stretches — desk work, driving, flights — often flares the pain.
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Flares with cough or sneeze
A cough, sneeze or straining bears down on the nerve root and sharpens the leg pain briefly.
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Numbness in a dermatome
A patch of numbness that follows a nerve-root map — not a random area.
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Red flag: cauda equina
Saddle numbness, urinary retention, bilateral leg weakness — call 999 or attend A&E immediately.
Treatment
How sciatica is treated in the UK.
A stepwise plan — medication and rehab first, targeted injections next, surgery for a select group. Here is what each option does.
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Simple analgesia and short-course NSAID
Paracetamol with a short course of NSAID — modest but useful for acute flares alongside graded activity.
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Neuropathic-pain medication
Amitriptyline or duloxetine for pain with a clear neuropathic pattern — nerve-driven leg pain.
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Physiotherapy programme
Structured, progressive movement — the foundation of rehab as the nerve settles over weeks.
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Nerve-root block or epidural steroid injection
Targeted steroid near the affected root — for pain that persists despite rehab and medication.
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CBT for chronic pain
Cognitive behavioural therapy targets fear, avoidance and low mood when pain is not settling.
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Radiofrequency ablation
A highly selected option for specific pain patterns — never a routine step for sciatica.
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Microdiscectomy
Removes the disc fragment pressing on the nerve root — for persistent radiculopathy from a clear structural cause.
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Foraminotomy or decompression
Widens the space around the nerve root — for foraminal or central stenosis with radiculopathy.
What this guide is based on
The sources behind every claim on this page.
UK national guidance and specialist society standards, current at the time of last review.
Key references
Guidelines and standards we relied on.
A quiet reminder
This guide is for information, not medical advice.
Your GP or pain team knows your history and can tell you which parts apply to you. If in doubt, get seen.
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NICE. Low back pain and sciatica in over 16s: assessment and management (NG59).
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British Association of Spine Surgeons. Standards for spinal care.
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Faculty of Pain Medicine. Standards and guidance.
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British Pain Society. Guidelines for chronic pain management.
Red flags
When sciatica becomes an emergency.
Most sciatica is managed patiently. These are the situations where waiting is the wrong call.
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Cauda equina symptoms
Saddle numbness, urinary retention, bilateral leg weakness — call 999 or attend A&E immediately.
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Progressive weakness
Worsening power in the leg or foot — urgent spinal review the same day.
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Fever with back pain
Concern for spinal infection (discitis, epidural abscess) — same-day medical assessment.
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Weight loss with back pain
Unexplained weight loss with new back or leg pain — needs investigation for underlying pathology.
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Cancer history
A change in pain pattern in someone with a cancer history warrants prompt imaging.
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Trauma with new neurology
A recent injury followed by new numbness, weakness or reflex change — image and refer urgently.
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Steroid use with new pain
Long-term steroid use raises fracture risk — new back or leg pain deserves imaging rather than watchful waiting.
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Osteoporotic fracture suspected
Sudden severe pain after minor loading in someone at risk — image to look for vertebral fracture.
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Discitis suspected
Fever, severe rest pain and elevated inflammatory markers — needs urgent spinal MRI and specialist input.
Living with it
Usually short-lived, and very manageable while it lasts.
Four things that make the biggest difference day to day — movement, a flare plan, mindset, and steady reviews.
A quiet reminder
Consistency beats intensity, every time.
Small, steady changes — kept up for weeks — do more than a heroic few days that does not last.
- 01 Movement
Keep moving within tolerance
Complete rest deconditions the back — steady, graded activity gives the nerve the best chance to settle.
- 02 Flares
Have a flare plan
Know your escalation ladder — analgesia, gentle movement, and when to contact your team.
- 03 Mindset
Pain is not damage
For most sciatica, hurt does not equal harm — pain-informed movement is safe as the nerve heals.
- 04 Reviews
Reassess regularly
A short review at 6 weeks keeps the plan honest — and catches red flags early if things change.
Frequently asked
Everything we get asked about sciatica.
Quick answers on natural history, imaging, red flags, injections and when surgery is the right call.
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What is sciatica?
Sciatica is leg pain radiating from the lower back through the buttock and down the leg in a nerve-root distribution — usually from an irritated L4, L5 or S1 nerve root. The leg pain typically dominates over the back pain and often follows a recognisable dermatome.
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Do I need an MRI straight away?
Not usually. MRI is not first-line for sciatica. It is reserved for red flags, progressive neurology, or leg pain that persists beyond 6 weeks despite treatment. Most episodes improve without imaging.
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How long does sciatica last?
Most people improve within 6–12 weeks with a stepwise plan of medication, graded activity and physiotherapy. A minority go on to need targeted injections or, occasionally, surgery.
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When is a steroid injection helpful?
An epidural steroid injection or nerve-root block may help specific patients — typically those with persistent radicular pain from a disc herniation that has not settled with rehab and medication. It is targeted, time-limited, and used alongside physiotherapy.
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When is surgery the right answer?
Surgery is reserved for a small, well-selected group — persistent radiculopathy from a clear structural cause, progressive weakness, or neurological compromise. Microdiscectomy and decompression are the common operations.
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What are the red flags I should never ignore?
Saddle numbness, urinary retention, bilateral leg weakness, and progressive neurological deficit are cauda equina symptoms — call 999 or attend A&E immediately. Fever with back pain, unexplained weight loss, and new pain with a cancer history also warrant urgent review.
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