Lumbar Disc Herniation
A lumbar disc herniation occurs when the soft inner portion of a spinal disc in the lower back pushes through a tear in the outer layer and extends into the spinal canal or nearby nerve openings. This can compress spinal nerves and lead to lower back pain, sciatica, numbness, tingling, or weakness in the leg or foot. Lumbar disc herniation is one of the most common causes of lower back and leg pain in adults, and most cases improve with conservative treatment over time.
What is it?
The lumbar spine consists of five vertebrae in the lower back separated by intervertebral discs that act as cushions, absorb stress, and allow flexibility and movement.
Each disc contains a strong outer ring called the annulus fibrosus and a softer gel-like center called the nucleus pulposus. Over time, aging, repetitive strain, degeneration, or injury may weaken the outer portion of the disc, allowing the inner material to bulge or protrude outward. Depending on the severity, this may appear as a disc bulge, protrusion, extrusion, or sequestration.
The symptoms caused by a lumbar disc herniation depend largely on the location and size of the herniation.
When disc material compresses or irritates a nearby spinal nerve root, it can produce lumbar radiculopathy, commonly called sciatica. Symptoms may include pain, numbness, tingling, burning sensations, or weakness radiating into the buttock, thigh, calf, or foot.
Large central herniations may compress the cauda equina, the bundle of nerves at the lower end of the spinal canal. In rare cases, this can result in cauda equina syndrome, a medical emergency.
Risk factors include aging, repetitive bending or lifting, obesity, smoking, prolonged sitting, physically demanding work, poor posture, and prior lower back injury.
MRI of the lumbar spine is the preferred imaging test for evaluating lumbar disc herniation because it provides detailed visualization of the discs, nerve roots, spinal canal, ligaments, and surrounding soft tissues. MRI helps determine the exact size and location of the herniation and whether nerve compression is present.
CT and X-ray are less sensitive for soft disc abnormalities but may help evaluate bone spurs, fractures, spinal alignment, or degenerative changes.
Electrodiagnostic studies such as EMG and nerve conduction testing may sometimes be used when symptoms and imaging findings do not clearly correlate.
Important to Know
Most lumbar disc herniations improve gradually over weeks to months with conservative treatment.
Non-surgical management often includes physical therapy, activity modification, posture and ergonomic improvements, stretching, anti-inflammatory medications, and home exercise programs.
Image-guided epidural steroid injections may help reduce inflammation and relieve symptoms in selected patients.
Surgery is generally reserved for patients with severe or progressive neurological symptoms, persistent disabling pain despite conservative care, or evidence of significant nerve compression.
It is important to recognize that disc bulges and even disc herniations are commonly seen on MRI in people without symptoms, particularly as part of normal aging. Imaging findings are interpreted together with symptoms and physical examination results rather than in isolation.
Follow-up imaging may be recommended if symptoms worsen or if surgical treatment is being considered.
Red flag symptoms include sudden leg weakness, foot drop, numbness in the groin or inner thighs (saddle anesthesia), loss of bowel or bladder control, or severe back pain after trauma. These symptoms require urgent medical evaluation because they may indicate cauda equina syndrome or another serious spinal condition.