Back (Lumbar)

Lumbar Disc Herniation

Name: Lumbar Disc Herniation
Creator: Dr. Kwang Lee

요추 추간판 탈출증

Herniated disc compressing the lumbar nerve root (sciatica)

Written and edited by Dr. Kwang Lee, D.C., L.Ac. · Updated 2026-10-04

How common: Very Common
Typical age: Ages 30–50

What is it?

The nucleus pulposus herniates posterolaterally through the annulus fibrosus, compressing the traversing nerve root. L4-L5 and L5-S1 are the most common levels.

Commonly affected: L4-L5 (most common), L5-S1

How it develops

Annular DegenerationRepetitive loading causes concentric tears in the annulus
Nuclear HerniationNucleus pulposus extrudes posterolaterally through annular defect
Nerve Root CompressionHerniated material compresses the exiting or traversing nerve root
Inflammatory SensitizationPLA2 release causes chemical irritation amplifying radicular pain

Symptoms

Radiculopathy (Sciatica)Dermatomal pain radiating from buttock to leg and foot
Low Back PainLumbar ache worse with flexion and prolonged sitting
ParesthesiaNumbness/tingling in foot and toes (dermatomal)
Valsalva AggravationRadicular pain worsens with coughing, sneezing, or straining
Motor WeaknessWeakness of ankle dorsiflexion (L5) or plantarflexion (S1)

How it is examined

Positive SLRStraight leg raise 30–70° reproduces radicular pain below knee
L5: Foot Drop SignWeak dorsiflexion — cannot heel-walk; extensor hallucis weak
S1: Reduced Achilles ReflexDiminished ankle jerk; weak plantarflexion; lateral foot numbness

Imaging

X-ray may show disc space narrowing and loss of lumbar lordosis. Used to rule out fracture/spondylolisthesis.

Disc space narrowing
Loss of lumbar lordosis
Marginal osteophytes

MRI (T2-weighted) is gold standard — directly shows disc herniation, nerve root compression, and thecal sac effacement.

Posterior disc herniation
Nerve root compression
T2 hypointense disc
Thecal sac effacement

Non-surgical care

Activity ModificationBrief rest 2–3 days; avoid aggravating positions; early gentle mobilization
NSAIDsIbuprofen/naproxen to reduce pain and perineural inflammation
Epidural Steroid InjectionReduces perineural inflammation; provides short-term radicular pain relief
Physical TherapyMcKenzie exercises, core stabilization, lumbar traction, and posture training

Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.

When surgery is considered

Failed 6 weeks conservative care, cauda equina syndrome, progressive neurological deficit

Procedures that may be discussed

Microdiscectomy (gold standard — 90%+ success)
Percutaneous endoscopic discectomy

Outlook

Over 90% improve within 6–12 weeks with conservative management.