OSLondon Pain ManagementAppointments

Best evidence · Patient guide

Sciatica and lumbar radicular pain

Pain travelling into the leg can be severe and disruptive. A useful assessment asks not only whether the symptoms are called sciatica, but which nerve may be involved, why it is irritated and what treatment is proportionate.

Seek urgent medical assessment

New difficulty passing or controlling urine, loss of bowel control, numbness around the genitals or saddle area, or rapidly worsening leg weakness may indicate cauda equina syndrome or another neurological emergency.

What the term means

NICE uses “sciatica” for leg pain arising from lumbosacral nerve-root pathology. “Lumbar radicular pain” is a more precise clinical term. Symptoms can include sharp, burning or electric pain, altered sensation and—less commonly—weakness in a pattern related to the affected nerve.

Pathophysiology: why a lumbar nerve root becomes painful

The sciatic nerve is formed from nerve roots arising in the lower lumbar and sacral spine. Most clinically important sciatica begins at one of these roots—commonly L5 or S1—rather than in the sciatic nerve itself. A disc prolapse can narrow the available space and deform a nerve root; degenerative narrowing of the lateral recess or neural foramen can produce a similar effect.

Mechanical compression is only part of the explanation. Contact between herniated disc material and a nerve root can trigger an inflammatory response, alter microcirculation and increase the excitability of sensory fibres. This helps explain why the size of a disc abnormality does not map neatly onto pain severity, and why MRI findings must be interpreted alongside the history and neurological examination.

With persistent symptoms, changes in peripheral and central sensory processing may amplify pain. Sleep, mood, fear of movement, physical deconditioning and work or social pressures do not make symptoms imaginary; they can influence how strongly pain is experienced and how quickly function returns.

How it is assessed

The consultation considers where pain travels, what brings it on, whether there is numbness or weakness, how function and sleep are affected, and whether any features suggest a different or more serious cause. Examination may assess strength, reflexes, sensation, spinal movement and nerve tension.

Imaging is not a diagnosis by itself. Disc bulges and age-related changes are common in people without pain. MRI is most valuable when the result could alter treatment or referral.

Evidence-based management

Information, activity and recovery. Many episodes improve without an operation. NICE recommends tailored information, support for self-management and encouragement to continue normal activities where possible. Exercise should be selected around the person’s needs, preferences and capabilities; manual therapy, if used, should form part of a package that includes exercise.

Imaging. MRI is not routinely required in a non-specialist setting. In specialist care it is most useful when the result is likely to change management—for example before a targeted procedure or surgical opinion, or where the clinical course is atypical.

Medicines. Medication decisions require individual assessment. NICE advises against gabapentinoids, other antiepileptics, oral corticosteroids and benzodiazepines for sciatica because overall benefit has not been demonstrated and harms occur. Opioids should not be offered for chronic sciatica. NSAIDs have limited evidence of benefit and recognised gastrointestinal, renal and cardiovascular risks; if used, NICE advises the lowest effective dose for the shortest appropriate period.

Epidural or nerve-root injection. NICE recommends considering epidural local anaesthetic and steroid for acute, severe sciatica. For a selected patient, an image-guided injection may reduce pain sufficiently to support sleep, movement and rehabilitation, but it is not a cure for every disc prolapse and is not recommended as a general treatment for non-specific low-back pain.

Surgical opinion. Decompression may be considered when non-surgical treatment has not improved pain or function and imaging demonstrates a cause consistent with the symptoms. A 2023 BMJ systematic review found that discectomy can provide faster relief for selected patients with disc-related sciatica, but the advantage over non-surgical care diminishes with time; the balance between speed of relief, procedural risk and the natural history should therefore be discussed.

Common questions

What is sciatica?

Sciatica describes pain related to irritation or compression of a nerve root in the lower spine. Pain commonly travels from the buttock into the leg and may be accompanied by tingling, numbness or weakness. The term describes a pattern of symptoms rather than a complete diagnosis.

Does sciatica always come from a slipped disc?

No. A disc prolapse is a common cause, particularly in younger adults, but narrowing around a nerve, age-related spinal change and less common conditions can produce a similar pattern.

Do I need an MRI scan?

Not routinely. NICE advises that imaging should be considered in a specialist setting when the result is likely to change management. A scan can show abnormalities that are not responsible for pain, so it must be interpreted alongside symptoms and examination findings.

When might an epidural or nerve-root injection help?

NICE recommends considering an epidural injection of local anaesthetic and steroid for acute and severe sciatica. It is most useful when the clinical pattern and imaging are consistent and the likely benefits, limitations and risks have been discussed.

When is a surgical opinion appropriate?

A surgical opinion may be considered when non-surgical treatment has not improved pain or function and imaging findings correspond with the sciatic symptoms. Progressive weakness or suspected cauda equina syndrome requires a more urgent pathway.

Evidence used

Written and clinically reviewed by Dr Oliver Seyfried · Last reviewed 13 August 2026