Back pain - injections

About injections for chronic back pain

Injections into or near your spine help deliver pain-reducing medicines directly to the source of pain and can ease chronic back pain or sciatica (shooting pain down one or both of your legs). The effects of a successful injection can vary but may last up to three months.

There are two medicines used in injections for chronic back pain. Local anaesthetic is used to block pain from the injected area. Steroids are used to reduce swelling and irritation (inflammation) in the injected area.

There are four injection techniques available for chronic back pain.

  • Epidural injection. This targets the space that surrounds your spinal cord.
  • Nerve root block injection (also known as transforaminal epidural injection). This targets individual nerves in your spine.
  • Intra-articular facet or sacroiliac joint injection. These target the joints that link the bones of your spine.
  • Medial branch block injection. This procedure is used to diagnose your back pain. It targets the nerve supply to your facet joint in your spine.

Epidural injections and nerve root block injections help ease sciatic pain so you can progress with physiotherapy or other rehabilitation. The evidence for these treatments and intra-articular facet joint injections is varied and they may not always help. Speak to your doctor for more information.

Medial branch block or sacroiliac joint injections help to identify the source of the pain so that your doctor can plan appropriate treatment.

The type of injection you have is based on your specific symptoms and the reason for having the injection.

What are the alternatives?

Other pain-relieving therapies can help to ease back pain, such as pain-relieving medicines, exercise, manual therapy (including spinal manipulation) and acupuncture. Improving your understanding of back pain and the ways you can manage your pain through education programmes can be helpful. Yoga and relaxation may also help ease back pain. There isn’t enough evidence to say whether TENS (transcutaneous electrical nerve stimulation) is effective at reducing chronic back pain.

Preparing for an injection for chronic back pain

An injection is usually done as a day-case procedure by a doctor who specialises in pain management. You will usually have an injection under local anaesthesia. This completely blocks pain from the injected area and you will stay awake during the procedure. Your doctor may offer you a sedative. This relieves anxiety and helps you to relax.

You should tell your doctor about any health conditions you have, such as diabetes, bleeding disorders and about any medicines that you may be taking, such as aspirin, clopidogrel, dabigatran or warfarin. You may be asked to stop taking certain medicines for several days before the procedure.

If you’re a woman of child bearing age, you must tell your doctor if you could be pregnant. X-rays are usually used during the procedure. They are safe for adults, but may harm your developing baby. If you’re pregnant, your doctor will talk about alternatives to the procedure.


What happens during an injection for chronic back pain?

The procedure takes 20 to 40 minutes and you may be asked to wear a gown.

Usually you will lie on your abdomen (tummy), but you may be asked to lie on your side with your knees drawn up and chin tucked in. This position helps to open up the space between the bones in your back.

If you’re having a sedative, your doctor will inject it into a vein in the back of your hand.

A machine called a fluoroscope is usually positioned close to the area being injected. This shows real-time X-ray images during the procedure and your doctor will use this to guide the needle into the correct place.

Your doctor will carefully select a point to inject by using X-rays and/or feeling for specific bones in your spine. He or she will clean the injection site with a sterile antiseptic wipe and inject the local anaesthetic so that you don't feel the injection needle going into your back.

Your doctor will carefully insert a thin, hollow needle into your back. You won't feel the needle going in, but once it has reached your spine, you may feel some discomfort. While the needle is being inserted, it's important that you don't move, as any movement makes positioning the needle more difficult. You must tell your doctor if you feel any pain or discomfort as this may indicate that the needle is going into the wrong area.

Your doctor will check the needle is correctly positioned (he or she will inject a special dye containing iodine that shows up on X-rays) before injecting the local anaesthetic and steroids into your spine.

Afterwards, he or she will take the needle out and cover the injection site with a plaster.

What to expect afterwards

Your legs may feel numb or tingly, but this will pass quickly. Your blood pressure will be monitored for about 30 minutes. You will be able to go home when you feel ready.

You will need to arrange for someone to drive you home. You should try to have a friend or relative stay with you for the first 24 hours, especially if you have had a sedative during the procedure.


Recovering from an injection for chronic back pain


The local anaesthetic will keep you pain-free for a while, but it's best to take things easy for the first 24 hours. After this, your back may start to feel sore again because the steroids take a few days to work. Your back pain or sciatica should start to improve within a few days of your injection.

You should be able to start physiotherapy within a week of your injection. It's important to remember injections aren’t a cure for back pain and it's the physical therapy that will help improve your medical condition in the long-term.

What are the risks?

As with every procedure, there are some risks associated with injections for chronic back pain. We have not included the chance of these happening as they are specific to you and differ for every person. Ask your doctor to explain how these risks apply to you.


Side-effects are the unwanted but mostly temporary effects you may get after having the procedure. There are a number of possible side-effects of an injection for chronic back pain including those listed below.

  • Loss of leg strength, muscle spasms and inability to pass urine.
  • Pain and tenderness in your back or leg. This usually gets worse before it improves.
  • High blood sugar levels. If you have diabetes, you will be carefully monitored after the injection, but you must also keep checking your sugar levels when you get home.
  • Feeling weak, dizzy or faint. The steroids can cause a drop in blood pressure.
  • Swelling of your hands and feet. The steroids can cause fluid retention.


Complications are when problems occur during or after the procedure.

Complications of an injection for chronic back pain are rare but can be very serious. Possible complications are listed below.

  • Severe headaches. The needle punctures a hole in the membrane covering your spinal cord, which can cause spinal fluid to leak causing headaches that last for up to a week.
  • Bleeding. The needle can cut a blood vessel.
  • Infection. Bacterial infection in your spine can be very serious and will need intense antibiotic treatment.
  • Loss of feeling. Inflammation or nerve damage can cause loss of feeling for up to three months.
  • Allergic reaction, such as a rash or itching.

Why may injections for chronic back pain affect blood sugar levels?


The injection itself has no effect on blood sugar levels. It's the steroids in the injection that cause blood sugar levels to rise.


Steroid medicines (corticosteroids) reduce inflammation and are used to ease back pain. But they also affect the balance of water and salts in your body. So the side-effects of having steroids include swelling in your hands, feet or joints (caused by fluid retention) and high blood sugar levels.

The rise in blood sugar levels becomes a problem if you have Type 1 diabetes. This is a condition in which the body can't control the amount of sugar (glucose) in the blood because it can't produce the hormone insulin. If you have diabetes, you should tell your doctor before having an injection for chronic back pain, so that he or she can give you appropriate advice.

At home, you must keep a close check on your blood sugar levels and make sure that you drink plenty of water and eat properly. You must contact your GP if your blood sugar levels are high.

For more information about the effects of steroids on blood sugar levels, ask your doctor.

What kind of exercise can I do to help my back after an injection for chronic back pain?


It's best to take it easy and start with gentle exercises such as walking and swimming to help reduce stiffness and discomfort in your back.


An injection isn't a cure for back pain. The aim of the injection is usually to give you a pain-free 'window' to progress with physical therapies. You should take it easy for the first few days after having an injection but you should aim to start a gentle exercise programme within a week of having your injection.

You can start by doing gentle walking and swimming, and following the programme of stretches and exercises given to you by your physiotherapist. These will improve the strength of your back and stomach muscles.

Can I have a repeat injection if my back pain returns?


Depending on the specific cause of your of back pain and the type of injection, it may be possible to have a repeat injection.


The benefits of an injection can last up to three months. Repeat injections into your facet joint or nerve root aren't usually recommended because of the risk of causing further irritation or damage. Sometimes, it may be possible to provide more long-term pain relief using radiofrequency treatment, where nerves signaling pain are exposed to heat.

If an injection into the epidural space helps reduce pain but the effects wear off and it becomes impossible for you to continue with gentle exercises, you may be able to have another injection.

For more information about a repeat injection, ask your doctor.