Sciatica & Nerve Compression

Sciatica is pain that travels along the path of the sciatic nerve — from the lower back, through the buttock, and down the leg. It is not a disease in itself but a symptom of an irritated or compressed nerve. Most cases resolve without surgery.

What’s happening

The sciatic nerve is the largest nerve in your body. It is formed from several nerve roots that exit your lower spine, join together in the pelvis, and travel down each leg. When one of those nerve roots is pinched or inflamed where it leaves the spine — most often by a herniated disc, but sometimes by bone spurs, narrowing of the spinal canal, or muscle tightness — the result is the burning, shooting pain we call sciatica.

Common symptoms

• Pain that radiates from the lower back or buttock down the back of the leg
• Sharp, burning, or electric pain — often on only one side
• Numbness, tingling, or a “pins and needles” feeling in part of the leg or foot
• Weakness in the leg, calf, or foot (for example, trouble lifting the foot or rising on tiptoe)
• Pain that gets worse with sitting, sneezing, coughing, or bending forward

Causes & risk factors

The most common cause is a lumbar disc herniation pressing on a nerve root. Other causes include lumbar spinal stenosis (a narrowing of the canal that houses the nerves), bone spurs from arthritis, spondylolisthesis (when one vertebra slips forward on another), and, less commonly, piriformis syndrome (irritation of the nerve as it passes through a deep buttock muscle). Risk factors include age 30–50, jobs with heavy lifting or long hours of sitting, obesity, diabetes, and smoking.

How it’s diagnosed

Your provider will ask about how the pain started, where it travels, and what makes it better or worse. The exam tests strength, reflexes, sensation, and a maneuver called the straight leg raise that reproduces nerve pain. Imaging isn’t always needed for typical first-time sciatica, but MRI is the test of choice if symptoms persist, are severe, or if weakness is present. X-rays and CT may be added in specific situations.

Treatment options

Non-surgical care helps the great majority of patients. Most episodes of sciatica improve within 6–12 weeks. Standard treatments include:

• Staying active with gentle walking; avoiding prolonged bed rest
• Physical therapy with stretching, core strengthening, and movement re-training
• Over-the-counter anti-inflammatory medication; short courses of stronger pain medication or oral steroids in selected cases
• Epidural steroid injections for severe or persistent leg pain
• Heat or ice and changes to sitting and lifting habits

Surgery is considered when leg pain remains disabling after 6–12 weeks of structured non-surgical care, when imaging shows clear nerve compression that matches your symptoms, or when there is significant or progressive muscle weakness. The most common operation is a microdiscectomy — a small, minimally invasive procedure to remove the piece of disc pinching the nerve. For sciatica caused by spinal stenosis, a laminectomy or other decompression may be recommended.

When to see a specialist

Schedule an evaluation if sciatica has not improved within 4–6 weeks, if pain is severe, or if numbness or weakness is worsening. Seek emergency care for loss of bowel or bladder control, numbness in the groin or inner thighs (sometimes called “saddle anesthesia”), or sudden severe leg weakness — these can be signs of a rare but serious condition called cauda equina syndrome that requires urgent surgery.