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Epidural injections

An epidural injection delivers anti-inflammatory medication into the space surrounding the spinal nerves. It is used mainly for leg or arm pain caused by an irritated or compressed nerve root, and works best when that pain is relatively recent.

When a nerve root is irritated — commonly by a disc protrusion or by narrowing of the space it passes through — pain is typically felt down the limb rather than in the spine. Inflammation around the nerve is a substantial part of that pain. An epidural injection places anti-inflammatory medication into the space around the nerve to reduce it.

Who it suits. Epidural injection is most useful for limb-dominant nerve root pain, particularly in the first weeks to months. It is less useful for pain confined to the back or neck, and less useful once symptoms have been present for a long time. If your main complaint is back pain rather than leg pain, this is probably not the right procedure.

What it can and cannot do. It does not remove a disc protrusion or widen a narrowed canal. What it can do is reduce inflammation enough to make the pain manageable while natural resolution occurs — and most nerve root pain does settle over weeks to months. For some people it also makes the difference between managing conservatively and proceeding to surgery, though it does not reliably prevent surgery.

How long benefit lasts. Highly variable. Some people get relief lasting months; others get days; some get none. The evidence overall supports short to medium term improvement in pain and function for nerve root pain, with the effect diminishing over time. Dr Martin will give you a realistic expectation rather than a single number.

On the day. You lie face down. Under X-ray guidance a needle is advanced into the epidural space between the vertebrae, with contrast used to confirm correct placement before injecting. Most people feel pressure. The procedure takes about 20–30 minutes. Light sedation is available.

Afterwards. Temporary increase in pain for a day or two is not unusual. Any benefit typically develops over several days to weeks, and the full effect may take four to six weeks. Arrange a driver if sedated.

Risks. Whilst pain procedures are generally safe and well tolerated, all procedures carry risks. The specific risks relevant to you and your procedure will be discussed with you, and written information provided, before you decide to proceed.

Urgent symptoms. Numbness around the buttocks or genitals, difficulty passing urine, loss of bowel control, or rapidly worsening weakness require emergency assessment, not an outpatient appointment. Go to an emergency department.