When sciatica refuses to settle, it can take over everything: sleep, work, walking, even sitting through a meal. An epidural injection for sciatica offers a non-surgical way to calm the irritated nerve, ease leg pain and create the breathing space needed to recover.
Dr. Purnajyoti Banerjee, Consultant Orthopaedic Spinal Surgeon and FRCS (Tr & Orth), offers image-guided spinal injections alongside his surgical practice at The Harley Street Hospital and LIPS Healthcare in Battersea. Because he performs both, he can advise honestly on whether an injection, physiotherapy or surgery is the right next step.
How Does an Nerve root block (Epidural) Injection Work?
Sciatica usually happens when a slipped disc or narrowing of the spinal canal presses on a nerve root in the lower back. The pressure, and the inflammation it triggers, causes the sharp, burning or electric pain that travels down the leg.
During a nerve root block (epidural) injection, a steroid and a local anaesthetic are delivered close to the irritated nerve. The steroid aims to reduce inflammation around the nerve, while the local anaesthetic provides short-term numbness. It is important to understand what an injection cannot do: it does not remove a disc bulge or widen a narrowed canal. Instead, it aims to settle the nerve while the body recovers.
Is an Epidural Right for You?
Most sciatica improves without any procedure. The NHS notes that sciatica usually gets better within a few weeks to a few months, so self-care, staying active and physiotherapy normally come first.
An injection is usually considered when leg pain is severe, persists despite these measures, or is preventing sleep, work or rehabilitation. NICE guidance on low back pain and sciatica (NG59) advises considering an epidural injection of local anaesthetic and steroid for people with acute and severe sciatica. Before recommending one, a specialist will usually examine you and review an MRI scan to confirm that the irritated nerve matches your symptoms.
An injection is not the right answer for every situation. If you develop numbness around your genitals or back passage, difficulty passing urine, loss of bladder or bowel control, or severe or worsening weakness in both legs, the NHS advises going to A&E or calling 999 immediately.
What Happens on the Day?
The procedure is usually carried out as a day case. According to patient information from The Dudley Group NHS Foundation Trust, you lie on your front, your back is cleaned, and X-ray imaging guides the needle to the correct position before the local anaesthetic and steroid are injected. The whole procedure takes around 20 to 25 minutes.
The medicine can be delivered by different routes. A transforaminal injection targets a single nerve root as it leaves the spine, an interlaminar injection spreads medicine more widely, and a caudal injection is given through the base of the spine. Your specialist will recommend the approach that best suits your scan and symptoms.
What to Expect Afterwards
The steroid does not work instantly. The Dudley Group leaflet explains that it usually takes 24 to 72 hours to begin working, with the greatest benefit felt within about a week, and that relief typically lasts a few weeks or months. Some people notice a temporary increase in pain for a few days before improvement begins. If sedation is used, you should not drive or operate machinery for 24 hours.
The period of reduced pain is valuable. Used well, it allows you to make progress with physiotherapy, walking and strengthening, which are key to longer-term recovery.
What Does the Evidence Show?
Honesty about results matters. A 2020 Cochrane review found that epidural steroid injections probably slightly reduce leg pain and disability in the short term, meaning up to around three months, although the average effects were small. In practice, responses vary: some people gain worthwhile relief, while others notice little change. This is why an injection works best as part of a wider plan rather than as a cure on its own.
Are There Any Risks?
Serious complications are rare, but every injection carries some risk. The Dudley Group leaflet lists common effects such as bruising at the injection site, a temporary drop in blood pressure and a short-lived increase in pain. Rare risks include headache, bleeding, infection, allergic reaction and, very rarely, nerve or spinal cord damage. Steroids can also temporarily raise blood sugar, which is relevant if you have diabetes. Your specialist will review your health and medicines, particularly blood thinners, before the procedure.
Common Questions
Will one injection be enough?
Not always. Some people need more than one injection to achieve good relief, while others benefit from a single injection. If symptoms return, your specialist will discuss whether another injection, more physiotherapy or a surgical opinion is the best next step.
Will an epidural cure my sciatica?
An injection does not remove the underlying cause, but by easing inflammation it can reduce pain while the nerve recovers. Combined with exercise and good advice, it can be an important step towards lasting improvement.
Take the Next Step Towards Easing Your Leg Pain
If sciatica is limiting your life, an accurate diagnosis is the best place to start. Dr. Purnajyoti Banerjee can assess your symptoms, review your scan and explain whether an epidural injection, physiotherapy or another treatment is most likely to help. Book your consultation with Dr. Banerjee.
