What is a peripheral nerve block? 

A peripheral nerve block is a type of regional anaesthetic used to numb a specific part of your body, such as an arm, leg, or shoulder. 

Local anaesthetic is injected near the nerves that supply the area being operated on. This blocks pain signals, so you do not feel pain during and after your procedure. 

You may have a nerve block: 

On its own (awake or with sedation). 

With a general anaesthetic (for better pain relief after surgery). 

When is a peripheral nerve block used? 

Peripheral nerve blocks are commonly used for: 

Arm and hand surgery. 

Shoulder surgery. 

Hip, knee, foot or ankle surgery. 

Some day‑case procedures. 

They can provide excellent pain relief for several hours after surgery. 

What are the benefits of a nerve block? 

Compared with general anaesthesia alone, nerve blocks may: 

Provide better pain relief after surgery. 

Reduce the need for strong painkillers (such as morphine). 

Cause less sickness and drowsiness. 

Help you recover and mobilise sooner. 

How is the nerve block done? 

Before the block 

Monitoring will be attached (heart rate, blood pressure, oxygen levels). 

A small plastic tube (cannula) is inserted into a vein. 

During the procedure 

The anaesthetist identifies the correct nerves using:  

Ultrasound (a scan) 

Sometimes a small nerve stimulator 

The skin is numbed with local anaesthetic 

A small needle is used to inject the anaesthetic near the nerve 

When a nerve block is combined with a general anaesthetic, the nerve block may be performed before or after you are asleep – your anaesthetist will discuss this with you. 

The procedure usually takes a short time, and you will be carefully monitored throughout. 

What will I feel? 

The injection may feel similar to having a blood test 

You may feel tingling or a “pins and needles” sensation briefly 

After the injection: 

The affected area will feel warm, numb, and weak. 

You may not be able to move it normally for several hours. 

This is normal and shows the block is working. 

During the operation 

You may be awake, or have sedation to help you relax. 

You will not feel pain, but you may feel movement or pressure. 

What happens after the operation? 

The numbness can last for several hours (sometimes longer). 

As it wears off, you may feel tingling before normal sensation returns. 

You will be given pain relief to take before the block wears off. 

Important safety advice 

Protect the numb area from injury (heat, pressure, sharp objects). 

Take care when walking if your leg is affected. 

Ask for help if you feel unsteady. 

What are the risks and side effects? 

Peripheral nerve blocks are generally very safe, but there are some possible risks. 

Common side effects 

Bruising or soreness at the injection site 

Less common risks 

Block may not work fully, requiring additional anaesthesia. 

Temporary nerve irritation (tingling, numbness, or weakness lasting days to weeks) 

Rare risks 

Infection at the injection site. 

Bleeding or damage to nearby structures. 

Local anaesthetic entering the bloodstream (causing symptoms such as dizziness or seizures – treated immediately). 

Nerve injury 

Most nerve symptoms are temporary and improve over time 

Permanent nerve damage is very rare 

Peripheral nerve blocks | The Royal College of Anaesthetists