Dorsal root ganglion block

An X-ray-guided injection of local anaesthetic, often with a steroid, around the dorsal root ganglion (a swelling on a spinal nerve as it leaves the spine), used to find out which nerve is causing arm or leg pain and to try to settle that pain for a while.

✓ Medically reviewed by a GMC-registered consultant · last reviewed September 2026 · next review September 2027 · how we review

In short

A dorsal root ganglion block numbs a specific spinal nerve to find out whether it is causing your arm or leg pain and to try to settle that pain for a while; it is usually not a cure.
Relief is often partial and temporary, and some people get little benefit, so expectations should be realistic.
It can help confirm which nerve is the source and inform decisions about further treatment or surgery.
It is done with X-ray guidance under local anaesthetic; serious nerve injury is extremely rare, but you should know the warning signs.

A plain-English summary. The detail — including risks and recovery — is below.

At a glance

TypeImage-guided injection (minor procedure)

AnaestheticLocal anaesthetic to numb the skin; you stay awake

How long it takesAbout 15 to 30 minutes

Hospital stayDay case; usually home the same day

Time off workUsually none to a day or two; some soreness is common

When you'll see resultsLocal anaesthetic may ease pain quickly; any steroid effect builds over days and is often temporary

On the NHS?Used in some NHS pain and spinal services, often when sciatica or a trapped nerve has not responded to other care

A general guide. Your specialist will give you advice for your situation.

Best fit

Can help confirm which nerve is causing your arm or leg pain

Pause if

Your pain does not fit a single nerve root, or another cause seems more likely.

Main recovery point

You may have numbness or weakness in the leg or arm while the local anaesthetic works. If your usual pain eases, note how much, as this is useful...

Good aftercare

Clear advice on the expected temporary numbness or weakness and when it is safe to drive.

First few hours

You may have numbness or weakness in the leg or arm while the local anaesthetic works. If your usual pain eases...

Same day to next day

Numbness and weakness wear off. A brief flare of soreness at the needle site is common. Keep the area dry for 24...

Days 2 to 7

If a steroid was used, any benefit usually starts to build. This is a good time to ease back into gentle movement...

2 to 6 weeks

The fuller effect, if any, is clearer. Note how much relief you got and how long it lasted, as this guides what to...

Medical line illustration of spine pain injection for Dorsal root ganglion block. — Illustration only - not a diagnosis, medical advice or a promise of result. Your anatomy and treatment plan may differ. Vuemedics does not publish before-and-after photos.

What is a dorsal root ganglion block?

As each nerve leaves the spine, it passes through a small swelling called the dorsal root ganglion, which carries sensation from part of the body. A dorsal root ganglion block (often called a nerve root block or transforaminal injection) places a small amount of local anaesthetic, often with a steroid, around this point using X-ray to guide the needle. Because the medicine can spread to the space around the spinal nerves, it is sometimes called a transforaminal epidural.

The block has two roles. As a test, it can show whether numbing a particular nerve takes your arm or leg pain away, which helps confirm which nerve is the source and can help plan further treatment or surgery. As a treatment, the steroid is hoped to calm inflammation around an irritated nerve, for example in sciatica, and settle the pain for a while.

It is important to be realistic. A dorsal root ganglion block is usually not a cure. Relief is often partial and temporary, lasting from a short time to some months, and some people get little benefit. It is best used as one step within a wider plan, alongside staying active, physiotherapy and, where relevant, decisions about surgery.

This is different from dorsal root ganglion stimulation, which is an implanted device used for some long-term nerve pain. A block is an injection, not an implant.

Types, options & approaches

There may be different ways to do this. The right approach depends on the clinical question and your circumstances.

Diagnostic block (local anaesthetic only)

Local anaesthetic alone is used to see whether numbing a specific nerve relieves your pain, helping confirm the source. The relief is short-lived by design.

Therapeutic block (with steroid)

Local anaesthetic plus a steroid, aiming to settle an irritated nerve, for example in sciatica. Benefit varies and is often temporary.

To help plan surgery

When it is unclear which nerve is responsible, a block can help predict whether surgery on that level is likely to relieve the pain.

Single or multiple levels

One or more nerve levels may be injected, depending on where the pain seems to come from.

Dorsal root ganglion block vs facet joint injection

Feature	Dorsal root ganglion block	Facet joint injection
Typical pain	Arm or leg pain (sciatica, trapped nerve)	Back or neck pain near the spine
Target	The nerve as it leaves the spine	The small joint at the back of the spine
Main purpose	Find the nerve and settle nerve pain	Test and settle joint pain
Can inform	Decisions about spinal surgery	Whether radiofrequency might help

They target different structures for different patterns of pain. Ask which fits your symptoms and why.

Preparing for your procedure

See a pain or spinal specialist who explains which nerve is suspected, whether the block is mainly a test or a treatment, and how it fits your wider plan.
Tell the team about all your medicines, especially blood thinners such as warfarin, clopidogrel or rivaroxaban, which may need adjusting.
Mention diabetes if a steroid is being used, as it can raise blood sugar for a few days, and any allergy to local anaesthetic or X-ray dye (contrast).
Tell the team if you might be pregnant, because X-ray guidance is usually avoided in pregnancy.
You can usually eat, drink and take your normal medicines unless told otherwise.
Arrange a lift home, as you should not drive for the rest of the day and may have temporary leg weakness or numbness.
Plan a quiet day or two afterwards and keep up your physiotherapy as advised.

What happens

You lie on an X-ray table, usually face down for a lower back nerve. The skin is cleaned and a small amount of local anaesthetic is injected, which stings briefly and then numbs the area. Using X-ray guidance, the specialist guides a fine needle towards the dorsal root ganglion. A little contrast dye is usually injected first to confirm the needle is correctly positioned before the medicine is given.

You stay awake and may feel pressure, or a brief reproduction of your usual nerve pain as the needle reaches the right spot, which can actually help confirm the target. The injection itself takes only a few minutes, with the whole appointment lasting about 15 to 30 minutes.

Afterwards you rest in a recovery area for a short time. You may have some numbness or weakness in the leg or arm for a few hours while the local anaesthetic works. You will often be asked to note how your pain behaves over the next hours and days, as this helps judge which nerve is involved and whether the block has helped.

Is this procedure right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

May not be suitable if…

Your pain does not fit a single nerve root, or another cause seems more likely.
You have an active infection, especially near the injection site, or are unwell.
You take blood thinners that cannot be safely paused, raising the bleeding risk near the nerve.
You have signs of serious nerve compression that need urgent surgical assessment, not an injection.
You expect a permanent cure from a single injection.

Delay or rearrange if…

You have a current infection, fever or feel unwell.
You might be pregnant, as X-ray guidance is usually avoided.
Your blood thinners have not yet been reviewed and adjusted.
You have new or worsening weakness, or any bladder or bowel symptoms, which need urgent assessment first.
Your diabetes is poorly controlled and a steroid is planned.

Alternatives to discuss

Staying active, physiotherapy and a structured self-management plan, which NICE supports for sciatica.
Time, as many episodes of sciatica settle with conservative care.
An epidural injection of local anaesthetic and steroid for acute, severe sciatica in selected people.
Surgery to relieve a trapped nerve if symptoms are severe or not settling.
Reviewing and optimising pain medicines rather than injecting, where appropriate.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

What matters most to me?

Think about symptoms, daily life, work, caring responsibilities, sport, fertility, travel, appearance and anxiety — the right choice depends on your priorities, not just the medical facts.

What are all my options?

Ask about waiting, monitoring, medicines, rehabilitation, a smaller or larger procedure, a different test, NHS referral, or a second opinion where that would help.

What would make me pause?

Active infection, pregnancy, unstable medical problems, smoking, medicines that increase bleeding, poor support at home, or feeling pressured are all reasons to slow down and get tailored advice.

What happens if I do nothing today?

For some problems, waiting is safe; for others, delay can make treatment harder. A good consultation should explain the trade-off in plain English.

Comfort, sedation or contrast choices

If local anaesthetic, sedation, contrast or pain relief is used, ask what is planned, why, and what it means afterwards.

Local anaesthetic

The usual approach. The skin and deeper tissues are numbed and you stay awake so you can give feedback if the needle reaches the nerve.

Benefits

Can help confirm which nerve is causing your arm or leg pain
May give a period of reduced pain that makes it easier to move and do physiotherapy
Can help decide whether surgery on a particular level is likely to help
Done with image guidance under local anaesthetic, without a general anaesthetic
May reduce reliance on painkillers for a time in those who respond

Risks & complications

More common

Temporary leg or arm weakness, numbness or pins and needles for a few hours
A brief flare of pain before any benefit shows
Bruising or tenderness where the needle went in
Facial flushing or feeling warm for a day or two if a steroid is used

Less common

Little or no improvement, so the block does not help
A short-lived rise in blood sugar if you have diabetes and a steroid is used
Headache, especially if the covering around the spinal cord is touched
Disturbed sleep, mood changes or a brief change in periods from the steroid

Rare but serious

Infection that may need antibiotics, very occasionally a deeper infection
Temporary or, very rarely, permanent nerve damage
An allergic reaction to the local anaesthetic or contrast dye
Bleeding around the nerve, which can press on it (very rare)

The most important points are that benefit is often partial and temporary, and that, while serious nerve injury is extremely rare, you should know the warning signs. Tell the team straight away during the procedure if you feel a sharp electric pain. Afterwards, seek urgent help for new or worsening weakness, numbness or any loss of bladder or bowel control. Ask your specialist which nerve they are targeting, what relief they expect, and what the plan is if it does not help.

Published figures to discuss

Reliable, comparable rates are hard to give because techniques, levels and patient groups vary, and the evidence for lasting benefit is mixed. Serious complications, including permanent nerve injury, are extremely rare, but the more common issue is limited or short-lived relief. Quoted figures should be treated as cautious estimates.

Figure	Reported range	How to interpret it	Source / confidence
Serious or permanent nerve injury	Extremely rare; quoted by NHS sources as less than 1 in 10,000	New or persistent weakness, numbness or bladder or bowel symptoms need urgent assessment; ask for clear emergency instructions.	NHS (Guy's and St Thomas') — Dorsal root ganglion blocks to treat painguysandstthomas.nhs.ukPublished figure
Temporary leg or arm weakness or numbness	Common in the first few hours from the local anaesthetic	Expected and settles; do not drive until it has fully gone.	Value of lumbar dorsal root ganglion blocks in predicting surgery response — PubMedpubmed.ncbi.nlm.nih.govSource-linked context
Bleeding or infection around the injection	Rare, but risk rises with anticoagulants, immune suppression and diabetes	Fever, spreading redness, severe new spinal pain or neurological symptoms need urgent advice.	Value of lumbar dorsal root ganglion blocks in predicting surgery response — PubMedpubmed.ncbi.nlm.nih.govSource-linked context
Diagnostic block result being misleading	Recognised, especially when pain fluctuates or placebo response is strong	A block should be interpreted alongside the pain pattern and functional change, not as a perfect test.	Guide sourcesClinical context

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

What happens afterwards

Recovery is usually short, but you may have some numbness or weakness in the limb for a few hours, and any benefit may show quickly or build over a few days.

First few hours

You may have numbness or weakness in the leg or arm while the local anaesthetic works. If your usual pain eases, note how much, as this is useful information. Do not drive until any numbness or weakness has fully gone.

Same day to next day

Numbness and weakness wear off. A brief flare of soreness at the needle site is common. Keep the area dry for 24 hours and take it easy.

Days 2 to 7

If a steroid was used, any benefit usually starts to build. This is a good time to ease back into gentle movement and physiotherapy.

2 to 6 weeks

The fuller effect, if any, is clearer. Note how much relief you got and how long it lasted, as this guides what to do next, including any decisions about surgery.

What's normal — and not a worry

Temporary numbness or weakness in the limb for a few hours
A brief flare of soreness at the needle site
Mild bruising or tenderness where the needle went in
Gradual, partial easing of pain rather than a sudden complete fix
Relief that may last a short time, weeks or, in some people, some months

Aftercare

Keep the injection site clean and dry for 24 hours.
Do not drive until any leg or arm numbness or weakness has completely gone; arrange a lift home.
Take care moving around at first, as a numb or weak limb can affect your balance.
Use simple pain relief such as paracetamol if you get a flare, unless told otherwise.
Keep up your physiotherapy and stay as active as your pain allows.
Keep a simple diary of your pain and how long any relief lasts.
Contact the clinic, your GP or, for urgent non-life-threatening advice, NHS 111 (in England, Scotland or Wales) if you notice signs of infection or new nerve symptoms. In Northern Ireland there is no region-wide 111 service, so contact your GP out-of-hours service or your HSC Trust's Phone First service instead. If it is a life-threatening emergency, call 999 or go to A&E.

Before your procedure

Someone to drive you home
A note of your usual medicines, especially blood thinners
Simple pain relief at home
A quiet day or two planned
A pain diary or notes app ready
The clinic's contact number and urgent-advice line saved

⚠ Get urgent help if…

New or worsening leg or arm weakness, numbness or pins and needles that does not settle within a few hours
Loss of control of your bladder or bowels, or numbness around the back passage (seek emergency help)
Spreading redness, heat, swelling or discharge at the injection site
Fever, chills or feeling generally unwell in the days afterwards
A severe headache, especially when sitting or standing up
Signs of a serious allergic reaction, such as a widespread rash, swelling or difficulty breathing (call 999)

Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your specialist gives you.

Results & realistic expectations

A helpful result is a clear reduction in your usual arm or leg pain after the block. If local anaesthetic was used, an early improvement that matches how long the anaesthetic lasts suggests that nerve is carrying your pain, which can help confirm the source and inform decisions about surgery. If a steroid was used, any benefit builds over a few days.

A dorsal root ganglion block cannot prove a long-term cure, and a poor response does not mean your pain is imaginary. It suggests that nerve is not the main source, or that an injection is not the right tool, and your specialist will use the result, with your scans and examination, to decide what to do next.

How long it lasts

Relief from a dorsal root ganglion block varies. A diagnostic block may last only hours; a therapeutic block with steroid may give weeks to some months of relief, and sometimes the irritated nerve settles for good as the underlying problem improves. Some people get little benefit. Blocks are not usually a permanent solution, and repeated blocks are used selectively rather than indefinitely.

Related tests, treatments or support

Dorsal root ganglion blocks are most useful alongside other care, such as physiotherapy and staying active for sciatica, and as part of planning if surgery is being considered. They are not a substitute for managing the underlying problem, and a responsible service will use them as one part of a plan rather than a stand-alone cure.

Follow-up & long-term care

You should have a review to discuss how much relief you got and how long it lasted, which guides whether to repeat the block, change approach or consider surgery. Report any new or worsening nerve symptoms, or signs of infection, straight away rather than waiting.

Keep up physiotherapy and activity alongside the block
Track how long any relief lasts so repeat blocks are only used when genuinely helpful
Use the result to inform, not replace, decisions about surgery or other treatment

Repeat, follow-on and what comes next

Diagnostic blocks may be repeated to confirm a finding before further treatment or surgery.
Therapeutic blocks are sometimes repeated, but not indefinitely if they do not help.
A poor response usually means that nerve is not the main source, prompting a change of approach.
A positive block can support, but does not by itself decide, whether to proceed to surgery.

Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.

What good aftercare looks like

Clear advice on the expected temporary numbness or weakness and when it is safe to drive.
A named contact route and clear advice to seek emergency care for new weakness or bladder or bowel symptoms.
A planned review to judge how much relief you got and how long it lasted.
Integration with physiotherapy and any decision about surgery rather than blocks alone.
An honest discussion of alternatives if the block does not help.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

The specialist's fee for assessing you and performing the block
The facility or imaging suite fee, including X-ray guidance
How many nerve levels and which side(s) are injected
Contrast dye and the medicines used, including any steroid
Follow-up appointments to review the result
Whether the same fee covers a repeat block if needed

Make sure your written quote includes

The specialist's fee and who will perform the block
The facility and imaging (X-ray) fee
How many levels and sides are included in the price
Medicines and contrast dye
A follow-up review to assess the result
What happens, and what it costs, if a repeat or different procedure is needed
The policy if the block gives little or no relief

On the NHS? Dorsal root ganglion blocks are used in some NHS pain and spinal services, often when sciatica or a trapped nerve has not responded to other care; private access may be used for speed or choice.

You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.

Choosing a specialist safely

Check the specialist is on the GMC Specialist Register for this area.
Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
You're entitled to time to consider and to have your questions answered before you agree — the specialist who looks after you should explain it, not a salesperson.
Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
You're entitled to your total cost in writing — including any follow-up — before you decide.

How Vuemedics verifies every consultant →

Questions to ask your medical professional

Take this to your consultation. A good specialist will welcome every one of these.

Which nerve are you targeting, and why do you think it is the source?
Is this block mainly a test, a treatment, or to help plan surgery?
What relief do you expect, and how long might it last?
How long might my leg or arm be numb or weak, and when can I drive?
What is the plan if it gives little or no relief?
How does this fit with my physiotherapy and any decision about surgery?
Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
Will you be the specialist who carries out my procedure, and who looks after me afterwards?
What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
What does a realistic result look like — and what can this procedure not achieve?
What are my options, including waiting, doing nothing for now, or choosing a different approach?
Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Frequently asked questions

Will a dorsal root ganglion block cure my sciatica?

Usually not on its own. It can help confirm which nerve is involved and settle the pain for a while, but relief is often partial and temporary. Sometimes the nerve settles for good as the underlying problem improves, but this cannot be promised.

Is this the same as a nerve root block or transforaminal injection?

Yes, these terms are often used for the same procedure. Because the medicine can spread to the space around the spinal nerves, it is also sometimes called a transforaminal epidural.

Why might my leg feel weak or numb afterwards?

The local anaesthetic can briefly affect the nerve, causing numbness or weakness for a few hours. This is expected and settles. Do not drive until it has completely gone.

Can it help decide about surgery?

Yes. When it is unclear which nerve is responsible, a block can help predict whether surgery on that level is likely to relieve your pain, which is useful information for you and your surgeon.

Can I get this on the NHS?

Yes, some NHS pain and spinal services offer it, often when sciatica or a trapped nerve has not responded to other care. Private access may be used for speed or choice.

What if it does not help?

That is useful information. It suggests that nerve is not the main source, or that an injection is not the right approach, and your specialist will discuss alternatives, including further assessment or surgery.

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How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: NHS (Guy's and St Thomas') — Dorsal root ganglion blocks to treat pain NHS (Hull University Teaching Hospitals) — Dorsal root ganglion / nerve root block / transforaminal injection NICE NG59 — Low back pain and sciatica in over 16s (recommendations) Faculty of Pain Medicine — Patient information leaflets Value of lumbar dorsal root ganglion blocks in predicting surgery response — PubMed nidirect — Urgent and emergency care services (Northern Ireland) nidirect — GP out-of-hours service (Northern Ireland)

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.