Sciatica: Causes, Symptoms and Treatment

Sciatica is not a diagnosis in itself — it is a symptom: pain that radiates from the lower back or buttock down the leg, following the path of the sciatic nerve. It is one of the most recognisable and debilitating presentations in musculoskeletal medicine, affecting approximately 5–10% of adults with low back pain and up to 40% of adults at some point in their lives.

The sciatic nerve is the longest nerve in the body — formed from spinal nerve roots L4, L5, S1, S2 and S3. It passes through the buttock, down the back of the thigh, branches behind the knee, and supplies the lower leg and foot through the tibial and common peroneal nerves.

What Causes Sciatica?

Lumbar Disc Herniation (Most Common)

The most frequent cause, responsible for approximately 85% of sciatica cases. The nucleus pulposus (gel core of an intervertebral disc) herniates through the annulus fibrosus and presses on a nerve root exiting the spinal canal.

• L4–L5 disc herniation — compresses the L5 nerve root; causes pain and numbness radiating to the outer shin and top of the foot; weakness of foot dorsiflexion (foot drop)
• L5–S1 disc herniation — the single most common level; compresses the S1 nerve root; causes pain and numbness radiating to the outer calf, heel, and little toe; reduced ankle reflex; weakness of plantarflexion (pushing down on the accelerator)

The herniated disc material causes pain through two mechanisms: direct mechanical compression of the nerve root, and a strong inflammatory response — prostaglandins, substance P, and cytokines released from the disc actively inflame the nerve root, producing the characteristic burning, radiating pain.

Lumbar Spinal Stenosis

Narrowing of the spinal canal due to OA-related bone and ligament overgrowth compresses nerve roots within the canal, producing neurogenic claudication — bilateral leg pain and heaviness on walking, that relieves with sitting (which opens the canal). This is the predominant cause of sciatica-type symptoms in adults over 60.

Piriformis Syndrome

The piriformis muscle (deep in the buttock) can compress or irritate the sciatic nerve where it passes nearby. Less common than disc herniation; typically causes buttock pain radiating down the leg without the clear dermatomal pattern of nerve root compression. Provoked by sitting and activities that stretch the piriformis.

Spondylolisthesis

Forward vertebral slippage narrows the foramen through which the nerve root exits, causing radiculopathy. More common at L4–L5.

Tumour or Infection

Rare but important — spinal metastasis, primary vertebral tumour, or epidural abscess can compress nerve roots. These causes present with red flag features (see below).

Symptoms

The hallmark is unilateral leg pain in a dermatomal distribution — the pain follows a specific pathway depending on which nerve root is affected.

Typical Features

• Pain character: sharp, shooting, burning, or electric shock-like; radiates from buttock into thigh, calf, and sometimes foot
• Unilateral: almost always one leg (bilateral sciatica from a central disc herniation suggests more serious pathology, including cauda equina syndrome)
• Aggravated by: sitting (especially driving), coughing, sneezing, straining — anything that increases intra-abdominal pressure compresses the herniated disc further
• Relieved by: walking, lying flat, lying in the foetal position

Neurological Symptoms

Depending on the nerve root involved:

Root	Pain Distribution	Numbness	Weakness	Reflex
L4	Inner shin to ankle	Inner calf	Knee extension (quadriceps)	Knee jerk ↓
L5	Outer shin to top of foot	Big toe and web space	Foot and big toe dorsiflexion	No reliable reflex
S1	Outer calf, heel, little toe	Outer foot	Plantarflexion (calf raise), eversion	Ankle jerk ↓

Red Flag Symptoms — Emergency Assessment Required

• Cauda equina syndrome: bilateral leg weakness, saddle anaesthesia (numbness in the perineum, inner thighs, genitals), urinary retention or incontinence, faecal incontinence — surgical emergency; present to hospital immediately
• Rapidly progressive neurological deficit (worsening foot drop or leg weakness)
• Night pain, fever, unexplained weight loss — consider infection or tumour

Diagnosis

Clinical Examination

Straight leg raise (SLR) test: the examiner lifts the patient's leg with the knee straight. Reproduction of the patient's radiating leg pain below the knee at less than 60° of elevation is highly sensitive for lumbar nerve root compression. The contralateral SLR (lifting the unaffected leg reproduces pain in the affected leg) is less sensitive but highly specific.

Neurological assessment: muscle power, reflexes (knee jerk, ankle jerk) and sensation tested in both legs to localise the affected nerve root.

MRI of the Lumbar Spine

The essential imaging investigation for sciatica with neurological features, failure of conservative treatment, or red flag symptoms. MRI clearly shows:

• The herniated disc and its relationship to the nerve root
• The level and severity of compression
• Whether the disc has extruded (broken through) or only bulged
• Spinal canal dimensions and signs of stenosis
• Ruling out tumour, infection or other serious pathology

MRI is not required in the first 4–6 weeks of typical sciatica without neurological deficit — most herniations resolve spontaneously, and early imaging does not change initial management.

CT Myelogram

If MRI is contraindicated (pacemaker, metal implants) or inconclusive, CT myelogram provides detailed images of nerve root compression.

Electrophysiology (EMG / Nerve Conduction Studies)

Helpful to confirm nerve root involvement, localise the level, and differentiate from peripheral nerve entrapment (e.g. peroneal nerve palsy at the fibular head mimicking L5 radiculopathy).

Treatment

Natural History — Most Sciatica Resolves

Approximately 70–90% of patients with sciatica from disc herniation improve significantly within 6–12 weeks with conservative management. The herniated disc material gradually retracts and the inflammatory response resolves. However, recovery can be slow and painful, and early treatment significantly reduces suffering during this period.

Conservative Management

Staying active — continuing normal activity as pain permits; bed rest prolongs recovery. Walking and gentle movement are preferred over immobilisation.

Analgesia:

• NSAIDs (naproxen, diclofenac, ibuprofen) — first-line; reduce inflammation at the nerve root; best taken regularly rather than as needed
• Paracetamol — modest additional benefit when combined with NSAIDs
• Neuropathic agents (gabapentin, pregabalin, amitriptyline, duloxetine) — address the burning, electric quality of radicular pain; generally preferred over opioids
• Short-term oral corticosteroids — rapidly reduce nerve root inflammation; may provide faster early relief

Physiotherapy — targeted exercises to centralise pain, nerve root mobilisation techniques (neural flossing/neural mobilisation), and core stabilisation

Heat therapy — helpful for associated muscle spasm

Epidural Steroid Injection (ESI)

A corticosteroid is injected into the epidural space at the level of the affected nerve root under fluoroscopic or CT guidance. This delivers anti-inflammatory medication directly to the inflamed nerve root, providing significant pain relief in 50–70% of patients.

ESI is most effective as a bridge treatment — providing enough relief to enable physiotherapy and daily activity while awaiting natural disc resolution. Typically 1–3 injections per course; not indefinitely repeated.

Approaches include:

• Transforaminal ESI — most targeted; delivers medication directly to the affected nerve root via the foramen
• Interlaminar ESI — between the laminae; broader distribution
• Caudal ESI — through the sacral hiatus; less specific but safe

Surgery

Surgery is indicated for:

1. Cauda equina syndrome — emergency microdiscectomy within hours; delay increases risk of permanent bladder/bowel dysfunction
2. Progressive neurological deficit — worsening foot drop or leg weakness despite conservative treatment
3. Severe, disabling pain not adequately controlled after 6–12 weeks of optimal conservative management
4. Patient choice — some patients prefer earlier surgical relief rather than waiting months for natural resolution

Microdiscectomy
The standard surgical treatment for lumbar disc herniation causing sciatica. A small incision is made over the affected level; under microscopic magnification or an endoscope, the herniated disc fragment is removed. The nerve root is decompressed while leaving the rest of the disc intact.

Outcomes:

• Leg pain relief: >90% of appropriately selected patients experience significant improvement
• Earlier return to normal activity compared to conservative management
• Surgery does not improve back pain — it relieves the leg symptoms caused by nerve compression
• Recurrence rate: approximately 5–10% experience re-herniation at the same or adjacent level

Endoscopic discectomy — a newer minimally invasive technique using a small tube and endoscope; performed under local anaesthetic and sedation in some centres; day-case procedure; equivalent outcomes to traditional microdiscectomy in experienced hands.

Sciatica Treatment in China

China's spinal surgery centres offer:

• MRI and diagnosis: lumbar MRI, neurological assessment and pain specialist consultation
• CT-guided and fluoroscopy-guided ESI: interventional pain procedures available
• High-volume microdiscectomy: specialist spinal surgeons performing hundreds of microdiscectomies annually; endoscopic disc surgery available at leading centres
• Endoscopic (PELD) discectomy: percutaneous endoscopic lumbar discectomy — performed under local anaesthetic through a 7mm incision; day-case; available at specialist centres in Beijing and Shanghai
• Comprehensive neurophysiology: EMG and nerve conduction studies for complex cases
• Cost: care in China is generally less expensive than UK private treatment, but the hospital prices each case individually — ask us for the written quote before you commit.
• Full English navigation from first appointment through discharge planning and rehabilitation advice

Contact a ChinaMedicalTour care navigator to arrange a sciatica or spine assessment.

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Medical content based on MSD Manuals and international spine surgery evidence. Reviewed 2025.

Frequently Asked Questions

Can international patients get a remote MRI review for joint or spinal conditions before traveling?

Yes. Overseas patients can submit DICOM MRI, CT, or X-ray imaging for remote pre-consultation coordination with Chinese orthopedics and spine specialists to assess surgical vs conservative indications.

What minimally invasive orthopedic procedures are commonly evaluated in China?

High-volume orthopedic departments evaluate arthroscopic joint repair, total joint replacement (hip and knee arthroplasty), percutaneous spinal endoscopy, and structured post-operative physical rehabilitation.

How is hospital admission and post-operative mobility coordinated?

Inpatient observation duration, surgical scheduling, and mobilization milestones are established directly by the hospital care team, supported by bilingual coordination throughout the hospital stay.