Spinal Injections: Nerve Root Block, Epidural & Facet

Spinal injections are targeted procedures that place medication precisely near a structure in or around the spine. They are widely used as part of non-surgical care, both to help identify where pain is coming from and to provide a period of relief. This page explains the main types — nerve root blocks, epidural injections and facet joint blocks — how they are performed, and their balance of benefits and risks, to support an informed discussion with a spine specialist.

What are spinal injections?

A spinal injection delivers a small amount of medication to a specific target close to the spine. The medication is usually a local anaesthetic, which numbs the area, often combined with a steroid, which reduces inflammation around the structure being treated.

The purpose can be twofold. As a diagnostic tool, an injection to a single structure helps confirm whether that structure is the source of pain: if the pain eases after numbing it, this points to the origin. As a therapeutic tool, the same injection may settle inflammation and provide a window of relief that supports rehabilitation. Often a single injection serves both purposes.

The three common types target different structures:

• Nerve root block — medication placed around a single spinal nerve as it exits the spine.
• Epidural injection — medication delivered into the epidural space surrounding the nerves.
• Facet joint block — medication directed at one of the small facet joints at the back of the spine.

Who is a candidate? (Indications)

Spinal injections are considered when pain is thought to arise from a specific spinal structure and when a more precise diagnosis or a period of relief would be helpful.

Common situations include:

• Sciatica or arm pain from a nerve root irritated by a herniated disc or narrowing, where a nerve root block or epidural may help.
• Lumbar spinal stenosis, where an epidural injection may ease leg symptoms from crowded nerves.
• Suspected facet joint pain, where a facet block can help confirm the source and provide relief.
• Uncertain pain source, where a carefully chosen injection clarifies which structure is responsible before further decisions are made.

Injections are usually one part of a broader plan that includes physiotherapy, exercise and activity modification. They are generally not the first or only step, and selection depends on the pattern of symptoms and imaging.

How the procedure is performed

Spinal injections are typically performed as a short outpatient procedure, with the patient awake or lightly sedated. The broad steps are:

1. The patient is positioned to expose the target area, and the skin is cleaned and numbed.
2. Under live X-ray or other imaging, a fine needle is guided to the intended target — a nerve root, the epidural space or a facet joint.
3. A small amount of contrast dye may be used to confirm correct needle position before medication is given.
4. The medication, usually local anaesthetic with or without steroid, is injected.
5. The needle is removed and a small dressing applied.
6. The patient is observed for a short period and the early response to the injection is noted, which can itself be informative.

Image guidance and accuracy

Image guidance is central to modern spinal injections. Live X-ray, sometimes with contrast, or other imaging allows the needle to be placed accurately at the chosen structure and confirms its position before any medication is delivered.

This precision matters for both roles of the injection. For diagnosis, treating exactly the intended structure makes the result more meaningful. For treatment, accurate placement helps direct the medication where it is needed and supports safe practice. The choice of which structure to target is based on the symptoms and imaging.

Benefits and risks

Spinal injections are generally well tolerated, but as with any procedure the benefits should be weighed against the risks.

Potential benefits

• Help in identifying the source of pain, guiding further treatment.
• A period of pain relief that may support physiotherapy and a return to activity.
• A minimally invasive, outpatient option that may reduce or delay the need for surgery in some people.

Recognised risks

• A temporary increase in pain before any benefit is felt.
• Bleeding or infection at the site.
• Headache, particularly after some epidural procedures.
• A short-lived rise in blood sugar or other effects from steroid.
• Rarely, nerve irritation or other complications.

A specialist will explain how these apply and any precautions relevant to an individual.

Alternatives

Injections sit within a wider range of options for spinal pain.

• Physiotherapy and exercise, which form the foundation of non-surgical care for most spinal conditions.
• Medication and activity modification to manage symptoms while the problem settles.
• Surgery, considered when there is significant nerve or cord compression, instability, or symptoms that persist despite non-surgical measures.

Injections do not correct structural problems, so they complement rather than replace these other approaches.

Recovery and outlook

Recovery from the injection itself is usually quick. Most people go home the same day and resume normal activity within a day or two, following any specific advice given. Some notice soreness at the injection site initially.

The relief from a spinal injection varies considerably. Some people experience benefit lasting weeks or months, others a shorter time, and some little change. Any relief is often used as an opportunity to make progress with physiotherapy and graded activity. Because injections treat symptoms rather than the underlying structure, ongoing self-management remains important.

When to seek a specialist opinion

It is reasonable to seek a spine specialist’s view if back, neck, leg or arm pain persists despite physiotherapy and simple measures, or if the source of the pain is unclear and a more precise diagnosis would help guide treatment.

Certain symptoms call for prompt or urgent assessment, including progressive weakness, worsening numbness, or any loss of bladder or bowel control alongside spinal symptoms. A specialist can determine whether a spinal injection is appropriate, explain its diagnostic and therapeutic role, and place it within an overall plan of care.