Epidurolysis to treat pain

Chronic back and neck pain is very common. Pain can come from many different sources, such as joints, nerves, muscle tension, and ligaments.

Sometimes nerve irritation in the spine is a cause of pain. This can be caused by scar tissue (fibrosis) around the nerve, interfering with the blood flow to the nerve, or even pulling on the nerve itself. This sort of irritation can happen after common ‘wear and tear’ disc injuries, and can also happen after back surgery.

Epidural steroid injections are a common treatment for spinal nerve pain, and can help reduce nerve irritation by:

  • rinsing inflammatory substances off the nerve surfaces
  • reducing inflammation and swelling (becuase of the steroids included)
  • breaking or cutting inflammatory adhesions (a type of scar tissue) that tie the nerve to other structures

These injections will not always help. There are 2 reasons for this.

  • The injected medicine might not always reach the exact site of the problem, because the spread of the medicine in the epidural space is unreliable.
  • Epidural injections are unlikely to loosen mild scars, which might be the main problem.

Epidurolysis treats both of these issues. It is sometimes called a Racz procedure.

For this procedure, a thin, flexible tube (catheter) is put into the epidural space using X-ray guidance. Saline (sterile salt water) and a medicine called hyaluronidase are injected through the catheter to loosen scar tissue. Contrast (a dye that shows up on X-rays) is injected to monitor the spread of the medicine.

Finally, steroid medicine is injected into the target area. This technique allows us to give treatment more accurately, particularly to difficult areas that cannot be reached with simple epidural blocks.  

The injections are usually used alongside other treatments, such as physiotherapy.

Injection treatments are not always effective, and might not help your pain.

Side effects

As with any procedure, side effects can happen. These are usually minor, and there is only a small risk of serious harm.

Possible side effects include:

  • mild tenderness or bruising at the injection site, which usually settles over the first few days
  • some local anaesthetic spreading, causing some numbness and weakness in your legs and other areas. If this happens, the effect is temporary and will resolve over minutes, or sometimes hours
  • infection. This is rare. You should seek medical help if there is warmth or redness at the injection site, with tenderness, or you feel hot and unwell. This might need treatment with antibiotics
  • serious nerve injury. This is extremely rare (less than 1 in 10,000 cases)

Other treatment options

These will be discussed with you before you decide on any treatment. The decision about whether to have the injection is shared between you and your doctor. Your doctor can give you information about the chances of this being a successful treatment for you, and how this treatment fits into your care.

If you are unsure about having these injections, more information can be given, to make sure you are making an informed decision. Please speak to your doctor for more information.

We want to involve you in decisions about your care and treatment. If you decide to have the procedure or treatment, we will ask you to sign a consent form. This says that you understand what is involved and agree to have the treatment.

Read more about our consent process.

Before treatment

  • Always bring a list of all current medicines. This includes any you buy from a pharmacy or shop, and any herbal or homeopathic remedies.
  • Continue to take your medicines as usual on the treatment day (unless you are taking blood-thinning medicines (such as warfarin, rivaroxaban, heparin, or clopidogrel). If you take a blood-thinning medicine, or are unsure if you do, please contact us at least 2 weeks before your injection to help us manage these.

It is important to tell us before the procedure, if you:

  • have an infection in your body, or on the skin of your back (your doctor will delay the treatment until the infection is cleared)
  • are taking anticoagulant or antiplatelet medicines that thin the blood, such as warfarin, rivaroxaban, heparin or clopidogrel (this might need more preparation)
  • take anti-retroviral medicines (these can interact with the steroids used in the injections)
  • have diabetes (steroids might cause your blood sugar to change, needing monitoring and adjustment of your diabetic medicine)
  • have any allergies

You must also tell us if there is any chance that you could be pregnant. 

If you are planning to fly or travel abroad in the 2 weeks after the injections, please let us know as it might be best to change the date of the injection.

During treatment

Not all doctors give these injections in exactly the same way, but these things usually happen:

  • Blood pressure and pulse rate will be monitored.
  • A small needle (cannula) will be placed in the back of your hand.
  • You will be carefully positioned, and the skin around the injection sites will be cleaned with an antiseptic solution or spray. This can feel very cold.
  • X-ray (or other form of image guidance) will be used to make sure we give the injections accurately.
  • You will feel a stinging sensation as local anaesthetic is injected to numb the skin and surrounding tissues. Your doctor will tell you before it happens.
  • The doctor will give the injections to the areas suspected to be a source of pain. When the injections are given, you might feel pressure, tightness or a pushing sensation. If there is any discomfort, let the doctor know.

After the injections

You will be taken to a recovery area where nursing staff will monitor you. You will be told when you can get dressed, and be helped to sit up to make sure that you can stand safely after the procedure.

You will be given more advice when you are ready to leave hospital.

Leaving hospital

You can usually leave hospital within a few hours of the injection, and sometimes much sooner. This will depend on how long your doctor or nurse want you to stay for recovery.

Please make sure that you have made arrangements for someone to collect you after the procedure. If you don’t do this, your procedure will probably have to be cancelled.

It is unsafe for you to drive home immediately after the procedure. If you do so your motor insurance will be invalid.

Ideally, you should arrange for someone to stay with you for 24 hours. If that's not possible, you should at least have access to a phone.

For the first 24 hours after the procedure:


  • do resume taking your regular medicines, including painkillers, anti-inflammatory medicines and any that thin your blood
  • do monitor yourself for any symptoms of infection


  • do not drive
  • do not operate machinery
  • do not sign legal documents
  • do not provide childcare unsupervised
  • do not drink alcohol

If you are unsure, please discuss these issues with your doctor for more advice.

Before you go home you will be given information about who to contact if the pain unit is closed.

You might get some soreness or aching at the injection site. Do not worry if your pain feels worse for a few days as this sometimes happens.

If you have any sterile dressings, you can remove them before going to bed.

Keep the injection area dry for 24 hours after the procedure. Take your regular pain killers and medicines as normal and this should settle down. Try to keep moving about the house, but avoid doing anything too strenuous.

Contact the pain clinic if you:

  • have warmth, redness or soreness at the injection site
  • have fluid leaking from the injection site
  • feel hot and unwell
  • have a high temperature (fever) or are shivering
  • have severely increased pain

These could be a sign of infection.

Call the specialist nurses, phone: 020 7188 4714, Monday to Friday, 9am to 5pm.

Outside these hours contact your GP or phone 111.

In an emergency, go immediately to your nearest emergency department (A&E) or phone 999.

Returning to work

This will be different for everyone and will depend on the nature of your work. It is difficult to give general advice, so you should discuss this with your doctor.

The weeks after the injections

As your pain decreases, you should try to gently increase your exercise. Simple activities, like a daily walk, using an exercise bike or swimming on your back, will help to improve your muscle tone. It is best to increase your activities gradually. If you are unsure, or are finding exercises increasingly difficult, contact your GP or the pain team to discuss a referral to physiotherapy.

Follow-up appointments

You will receive details for your follow-up appointment. It will be a phone call with a nurse specialist, or in clinic with a consultant. If you haven’t heard from us within 10 weeks of the procedure, please talk to our nurses, phone: 020 7188 4714, Monday to Friday, 9am to 5pm.

Leaflet number: 5379/VER1
Last review: January 2024
Next review due: January 2027

Trusted Information Creator. Patient Information Forum

Contact us

If you have a problem at home, or are worried about your condition, please contact our specialist nurses at the pain management unit.

Phone: 020 7188 4714 or 020 7188 8877, Monday to Friday, 9am to 5pm.

Email: [email protected]

Outside of these hours, please contact your GP or NHS 111.

This information is adapted from the leaflets provided by the Faculty of Pan Medicine of the Royal College of Anaesthetists. Contributions from Addenbrooks Pain Management Unit, the Chronic Pain Service St Georges Hospital London, Newcastle Pain Management Unit and the Interventional Specialist Interest of the British Pain Society.

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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