Local anaesthesia

Local anaesthesia is when a part of your body is numbed with a medicine called a local anaesthetic. You may have a local anaesthetic to stop pain during and after surgery. Or you may use a local anaesthetic to treat a painful condition such as a sore throat.

How does a local anaesthetic work?

A local anaesthetic works by blocking the way your nerves carry pain signals to your brain. This numbing effect lasts for a short while. You’re still awake and aware of what’s going on around you, but you can’t feel any pain. You usually just feel some touch and pressure sensations instead.

When would I have a local anaesthetic?

You may have a local anaesthetic before you have:

• a needle put in your skin if you’re having an injection or a blood test
• a tube (called a cannula) put into a vein on the back of your hand before surgery
• dental treatment – for example, having a tooth taken out
• a minor procedure – this could be anything from a gastroscopy to having a skin lesion removed
• an eye operation – for example, having a cataract removed

You may also use a local anaesthetic to treat a painful condition such as:

• a sore throat
• haemorrhoids (piles)
• mouth ulcers
• sore nipples when you’re breastfeeding

Regional anaesthesia is a type of local anaesthesia that you may have to:

• numb a specific part of your body, such as your pelvis or legs, before an operation
• ease pain during labour and childbirth (an epidural or spinal anaesthetic)

Sometimes, you may have a combination of different types of anaesthesia. For example, you may have an operation under general anaesthesia, then a local or regional anaesthetic to ease pain afterwards.

Types of local anaesthesia

There are three main types of local anaesthesia:

• topical anaesthesia
• local anaesthetic injections
• regional anaesthesia

Topical anaesthesia

This is when you have a local anaesthetic put on your skin. It may be in the form of a gel or cream, drops, an ointment or a spray. It may be used to numb the area before you have an injection or implant, so you don’t feel pain from the needle.

Local anaesthetic injections

A local anaesthetic can be injected just under your skin to target the nerves that make you feel pain. Your skin and the area just below it will feel numb afterwards. You may have this before a minor surgical procedure.

Regional anaesthesia

For regional anaesthesia, your doctor or anaesthetist will inject a local anaesthetic near a nerve. This is to numb a large area or an area deep inside your body. There are three types of regional anaesthesia.

Spinal anaesthetics

A spinal anaesthetic is injected into the fluid around your spinal cord to numb your legs and the area below your belly button. This may be used before some types of surgery – for example, a hip replacement.

Epidural anaesthetics

You have an epidural anaesthetic through a small tube that’s put into your back. The anaesthetic can be topped up through the tube as you need it to ease any pain. Epidural anaesthesia can focus on a specific part of your body such as your bladder, and can be used before a Caesarean section. It can also be used for surgery and pain relief, and lower back and leg pain.

Nerve block

If you have a nerve block, the local anaesthetic is injected into the tissues around a particular nerve. This blocks the sensation to an area such as your hand, leg or head before you have a surgical procedure.

How quickly will I recover from a local anaesthetic?

After local anaesthesia, you may be able to go home on the same day. If you have a sedative, you’ll need to be monitored for a while afterwards but will usually be able to go home on the same day. How quickly you recover will depend on which type of anaesthetic you had.

If you have regional anaesthesia, it will take some hours before you get your feeling back. It’s important to protect the area while you’re still feeling numb, so you don’t hurt yourself. As your feeling returns, you may notice a tingling sensation.

Your doctor may recommend you take painkillers as the local anaesthetic wears off. Ask your anaesthetist or nurse about when you’ll be able to eat and drink afterwards. This will depend on which type of anaesthesia and which surgery or procedure you’ve had.

Driving after local anaesthesia

Whether or not you can drive after local anaesthesia depends on which type of procedure you’ve had. It will also depend on whether or not your anaesthetic will affect how well you can drive.

If you were given a sedative as well as local anaesthetic, wait at least 24 hours before you drive. Ask your doctor for advice. Legally, it’s your responsibility to remain in control of a vehicle at all times. So, if your procedure or anaesthetic affects this in any way, it’s best to wait. You’ll also need to check your car insurance policy.

What are the side-effects of local anaesthesia?

Side-effects of local anaesthesia are unwanted but mostly temporary effects that you may have after having a local anaesthetic.

You may notice a stinging sensation when the local anaesthetic is injected into your skin. You may get a bit of pain when an epidural or spinal anaesthetic is injected. You may also get:

• some redness of your skin – this may be caused by an allergy
• some bruising around the skin where you were given the local anaesthetic
• an infection
• some bleeding at the injection site

With some types of local anaesthetic, you may also get:

• a headache (if you have spinal anaesthesia)
• damage to nerves (if you have regional anaesthesia) – this doesn’t usually last for very long

Most people don’t react badly to local anaesthetics. But you can get a very severe allergic reaction called anaphylaxis. Or you could have problems with your heart and nervous system. Ask your anaesthetist for more information.

What are the alternatives to local anaesthesia?

You may have general anaesthesia instead. This is when you're asleep during the operation. Having general anaesthesia isn’t as safe as local anaesthesia and you may take longer to recover afterwards. But you may prefer to be unconscious during your procedure. You can discuss your options with your anaesthetist or surgeon.

If you’re having dental surgery, you’re more likely to have a general anaesthetic if you:

• are very anxious
• have an infection around the injection site
• are prone to bleeding problems
• are having major surgery

If you don’t want to stay awake for a procedure but are having a local anaesthetic, you may be able to have a sedative. This means you’re in a sleep-like state but won’t be unconscious.

After surgery, you may be able to have other painkilling medicines, such as morphine. You may have morphine into a vein through an intravenous drip which you can control yourself. This is called patient-controlled analgesia (PCA).