Anesthesia
Epidural Anesthesia Explained
An epidural numbs your body from a chosen level downwards through a fine tube left in your back, so pain relief can be topped up for as long as you need it. Here is exactly how it is done and what to expect.
The short version
What an epidural actually is
An epidural is a way of delivering local anaesthetic to the nerves as they leave your spine, so it blocks pain signals before they reach your brain. The key feature is the catheter — a very fine, soft tube that stays in your back during and after surgery. Because the tube stays in, your anaesthetist can keep topping up the medicine, run a continuous infusion, or strengthen the block if you need an operation rather than just pain relief.
Epidurals are used for major abdominal, chest, and lower-limb surgery (often alongside a general anaesthetic for pain control afterwards), for caesarean sections, and very commonly for pain relief during labour. The level it numbs depends on where in your spine it is placed — it can cover the lower body for a hip operation or the chest and abdomen for bigger surgery.
It is one of several options your team may discuss with you. If you want the bigger picture, see our overview of the main types of anaesthesia.
How the epidural is placed
You will be asked to sit on the edge of the bed and curl forwards — chin to chest, shoulders rounded, like a prawn — or to lie curled on your side. Arching your back open in this way separates the bones of your spine and makes space for the needle. Staying still and relaxed for a few minutes is the most helpful thing you can do.
- The skin on your back is cleaned with cold antiseptic and a small injection of local anaesthetic numbs the spot — this is the part that stings briefly, like a bee sting.
- The anaesthetist passes a needle into the epidural space, then threads the fine catheter through it and removes the needle, leaving only the soft tube taped securely up your back and over your shoulder.
- You may feel pushing or pressure in your back, which is normal. Sharp shooting pains or pins-and-needles down a leg are worth mentioning straight away, but are usually brief.
Local anaesthetic is then given through the catheter and the block builds up over 15 to 30 minutes.
What you feel as it works
As the block sets in, most people notice a spreading warmth, then heaviness, then numbness moving down from the level chosen. Your legs may feel weak, heavy, or hard to move — this is expected and means the epidural is working, not a sign anything is wrong.
You can usually still feel touch, pressure, and movement to some degree even when pain is well controlled, so during surgery you might be aware of pulling or pushing without it hurting. You may be kept fully awake, or given sedation to make you relaxed and drowsy depending on the operation and your preference. For a caesarean, mothers are typically awake so they can meet their baby.
Common effects and the small risks
Most side effects are mild, expected, and managed by your team as they happen:
- Low blood pressure is the most common effect, because the block relaxes blood vessels. You will have a drip and your pressure monitored closely; fluids or medicine fix it quickly, which is one reason you may feel a little lightheaded or shivery at first.
- Heavy, weak legs until it wears off — you will not be able to walk safely, so you stay in bed and are helped to move.
- A urinary catheter is often placed, because a numb lower body makes it hard to feel or pass urine.
- Shivering is common and harmless. Itching can occur if pain-relieving opioids are added to the epidural mixture, and is usually easily treated.
Less common is a headache (from the needle, treatable if it happens). Serious problems — lasting nerve damage, infection, or bleeding around the spine — are rare. Because these need treating quickly, tell your team promptly about any of the following: new or worsening severe back pain, fever, leg weakness or numbness that is getting worse rather than better, a block that is not wearing off on schedule or returns after starting to fade, or problems passing urine. Do not wait until the block was expected to have worn off — raise these straight away, including while the epidural is still running.
How long it lasts and how it wears off
Because of the catheter, an epidural lasts as long as it is topped up — that may be just for the operation, or for a day or two afterwards as a pain-relief infusion. When the medicine is stopped, the numbness fades gradually, usually over a few hours and generally from the toes upwards. How long it takes depends on which local anaesthetic was used, and it tends to be longer and more variable after a continuous infusion that has been running for a while. Sensation and the ability to move return before full normal feeling does.
As it wears off, pain relief is switched to tablets or other methods so you stay comfortable. Do not try to stand or walk until staff have checked that your leg strength and balance are back — and tell them if the numbness or weakness is not receding as expected. If you want a rough sense of timing for a related block, our nerve block wear-off timer can help you picture the recovery curve.
Epidural versus spinal anaesthetic
Epidurals and spinals are close cousins and are sometimes even combined, but they are not the same:
- A spinal is a single injection of local anaesthetic into the cerebrospinal fluid that surrounds the spinal nerves. It works fast, gives a dense, reliable block, and is ideal for shorter operations — but it is a one-shot dose that cannot be topped up and wears off on its own.
- An epidural uses a catheter that stays in place, so it builds up a little more slowly but can be topped up or run continuously for hours or days, which makes it the better choice for longer surgery and for ongoing pain relief.
Your anaesthetist chooses based on the operation, how long pain relief is needed, and your own health. Read more in our guide to spinal anaesthesia.
Spinal vs epidural at a glance
Frequently asked questions
Will I be awake during an epidural?
You can be either awake or lightly sedated — it depends on the operation and what you prefer. For labour and most caesareans, mothers stay awake so they are alert and can meet their baby. For bigger surgery, an epidural is often combined with sedation or a general anaesthetic so you are asleep, with the epidural mainly handling pain relief afterwards. Your anaesthetist will agree the plan with you beforehand.
Does having an epidural hurt?
The only sharp part is the small injection of local anaesthetic that numbs your skin first — it stings briefly, like a bee sting. After that you usually feel pushing or pressure in your back rather than pain as the catheter is placed. Staying still and curled forward makes it quicker and easier. If you feel a sharp twinge or pins-and-needles down a leg, just tell your anaesthetist.
How is an epidural different from a spinal?
A spinal is a single injection that works fast and wears off on its own, ideal for shorter operations. An epidural uses a thin catheter left in your back, so the anaesthetic can be topped up or run continuously for hours or even days. That makes epidurals better for longer surgery and for pain relief afterwards. They are sometimes combined. See our pages on spinal anaesthesia and types of anaesthesia for more.
How long until an epidural wears off?
Once the medicine is stopped, the numbness usually fades over a few hours, generally from the toes upwards. It can take longer and is more variable after a continuous infusion that has been running for a day or two, and depends on which local anaesthetic was used. Movement and strength tend to return before full normal sensation does. Your legs may feel heavy or wobbly at first, so do not stand or walk until staff confirm your leg strength and balance are back. Tell staff if the numbness or weakness is not wearing off as expected, and pain relief is switched to tablets or other methods as the block fades.