What is Lumbar Disc Prolapse?
Injury to a lumbar disc in which the soft, jelly-like nucleus pushes out through a tear or weakness in the surrounding annulus, sometimes pressing on a nearby nerve root. Patterns range from a broad bulge, to a focal protrusion, an extrusion, or a sequestrated free fragment floating in the spinal canal.
Causes
Age-related disc change (loss of water content), poor lifting technique (bending and twisting under load), repetitive lifting at work or in sport, being overweight, a sedentary lifestyle and prolonged sitting, smoking (accelerates disc degeneration), genetic predisposition. Pain comes from both direct pressure on the nerve and chemical inflammation from leaked nucleus material.
Symptoms
Mechanical low back pain (dull ache or sharp pain, often worse with bending, sitting and prolonged standing); sciatica — sharp, burning or shooting leg pain along a specific nerve distribution, often more severe than the back pain; pins and needles or numbness in part of the leg or foot; specific muscle weakness (e.g. foot drop). Leg pain is often the dominant feature.
Diagnosis
Detailed history of the pattern, triggers and neurological features. Examination of spinal range, gait, and a focused neurological assessment of the legs (strength, sensation, reflexes), with provocative tests such as straight-leg raise.
Imaging
MRI is the investigation of choice — it shows the disc, the nerves and any inflammation in detail. CT is used when MRI is contraindicated, or when bony anatomy needs to be defined. X-ray is useful for alignment, instability and degenerative change but does not directly show the disc. Imaging is always interpreted alongside symptoms and examination — abnormalities are common in people without pain.
Treatment
Most herniations settle on their own — studies show that herniated material shrinks by 60–80% and most patients improve within 6–12 weeks. Non-surgical care: short period of relative rest, structured exercise (core, gluteal, postural, nerve-mobilisation work), medications (paracetamol, NSAIDs, nerve-pain agents, short opioid courses for severe flares), CT-guided transforaminal or selective nerve-root steroid injections, and lifestyle measures. Surgery (typically microdiscectomy) is considered for severe persistent leg pain despite 6–12 weeks of conservative care, significant or progressive weakness, or cauda equina syndrome. It is considered earlier that this if pain is not able to be controlled, or if there is neurological weakness.