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.
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 does sciatica mean?
Sciatica means pain travelling into the leg because a nerve leaving the lower spine is irritated. Doctors may call this “lumbar radicular pain”. The pain can feel sharp, burning or electric and may come with tingling, numbness or, less commonly, weakness.
Why does the nerve become painful?
The sciatic nerve is made from several smaller nerve roots that leave the lower spine. Sciatica usually begins at one of these roots—most often L5 or S1—rather than lower down in the sciatic nerve itself. A disc prolapse can press on a nerve. Age-related narrowing around the nerve can do the same.
Pressure is only part of the explanation. Disc material can also irritate and inflame the nerve. This helps explain why a large disc prolapse does not always cause severe pain, while a smaller one sometimes does. An MRI therefore needs to be considered alongside the symptoms and examination.
When pain continues, the nervous system can become more sensitive. Poor sleep, fear of movement, loss of fitness, mood and pressures at work or home can then make recovery harder. This does not mean that the pain is imagined.
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. Read the detailed guide: Do I need an MRI for sciatica?
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. Learn when an MRI may be useful for sciatica.
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.
When might specialist assessment be useful?
Specialist assessment may be helpful when sciatica is severe or persistent, when pain below the knee is accompanied by numbness or weakness, when the diagnosis is uncertain, or when symptoms and MRI findings need to be considered together.
Dr Seyfried assesses patients with sciatica and lumbar radicular pain in London, including people for whom an image-guided nerve-root injection or a spinal surgical opinion may be under consideration. Read more about Dr Oliver Seyfried’s clinical practice and credentials.
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
- NICE guideline NG59: Low back pain and sciatica in over 16s: assessment and management.
- Jensen RK et al. Diagnosis and treatment of sciatica. BMJ. 2019;367:l6273.
- Machado GC et al. Surgical versus non-surgical treatment for sciatica: systematic review and meta-analysis of randomised controlled trials. BMJ. 2023;381:e070730.
- Seyfried O. Acute back pain and cauda equina. Medicine. 2018;46(12). DOI: 10.1016/j.mpmed.2018.09.011.
Written and clinically reviewed by Dr Oliver Seyfried · Last reviewed 13 August 2026