Spinal stenosis

3 things to know first

1. It is not cancer. Spinal stenosis is a structural narrowing, not a tumor or growth.
2. Symptoms matter more than the image. Some people have severe-looking narrowing on scans but little discomfort, while others have significant symptoms with mild narrowing.
3. It usually develops slowly. Most cases are related to age-related wear and tear.

What it is

Spinal stenosis means the spaces inside the spine have become narrower than usual. This can happen in the central canal (where the spinal cord runs), the lateral recesses, or the openings where individual nerves exit (the neural foramina).

The narrowing can be caused by thickened ligaments, overgrown facet joints, bulging discs, or bone spurs. When the space becomes tight, it can put pressure on the spinal cord or nerve roots.

Why it appears on your report

Radiologists describe spinal stenosis on MRI or CT when they see reduced space around the spinal cord or nerves. The report may specify where the narrowing is located (for example, the lower back or neck) and how severe it appears.

How serious is it

The seriousness of spinal stenosis is judged mainly by symptoms, not just by the degree of narrowing:

• Mild or no symptoms — often managed with exercise, physical therapy, and observation.
• Nerve pain, numbness, or tingling in the arms or legs — may need targeted treatment.
• Weakness or balance problems — usually warrant closer evaluation.
• Severe compression of the spinal cord — rare, but may require urgent intervention.

Imaging severity and symptoms do not always match. Your doctor will consider both.

When to seek care urgently

Go to emergency care or call emergency services if you have:

• New or worsening weakness in an arm or leg
• Loss of bladder or bowel control
• Numbness in the groin or inner thighs (saddle anesthesia)
• Severe, rapidly worsening back or neck pain with neurological symptoms

These can be signs of serious nerve or spinal cord compression.

What usually happens next

1. Symptom review and physical exam. Your doctor will check strength, sensation, reflexes, and walking pattern.
2. Correlate imaging with symptoms. The scan is interpreted alongside your history.
3. Conservative management. Physical therapy, targeted exercises, pain medications, and sometimes epidural injections are first-line treatments.
4. Surgical evaluation if needed. If symptoms are severe, progressive, or do not improve after conservative care, a spine surgeon may discuss decompression procedures.

A simple analogy

Imagine a garden hose running through a tunnel. If the tunnel walls slowly thicken and narrow, the hose becomes pinched. Water may still flow, but with less pressure and sometimes in spurts. Similarly, a narrowed spinal canal can irritate the nerves without completely blocking them.

Further reading

• Mayo Clinic — Spinal stenosis
• NHS — Spinal stenosis