What is a local anaesthetic?

A local anaesthetic is a type of medicine used to numb a part of your body for a short time. Local anaesthetics do not cause a loss of consciousness in the way that a general anaesthetic does. If you have a local anaesthetic, you will be awake and aware of what is happening around you, but you won’t feel pain in the area being treated.

A local anaesthetic has fewer side effects than a general anaesthetic. It is generally preferred when only a small part of your body needs to be numbed. When a local anaesthetic takes effect, you will feel no pain in the part of the body where the local anaesthetic is given or applied, but you may still sense pressure or movement.

How does local anaesthetic work?

A local anaesthetic works by blocking the nerves from the affected part of your body, so that they cannot transmit pain signals to your brain. The blocked nerve transmission means the affected part of your body will feel numb. The numbing effect usually occurs within minutes and may last for a few hours.

What are the different types of local anaesthetic?

Types of local anaesthetics include creams, drops, sprays or injections.

A local anaesthetic is used most often for surgery on small areas of your body, such as minor skin surgery or the extraction of a wisdom tooth.

Topical anaesthetic

Topical anaesthetics are available as liquids, creams, patches or ointments, and are used on the surface of the body. For instance, some types of eye surgery can be performed using eye drops containing local anaesthetic.

Some topical anaesthetics are available over-the-counter in pharmacies.

Epidural and spinal anaesthesia

An epidural block and a spinal block both involve the injection of local anaesthetic into the fluid that surrounds the spine.

Epidural and spinal anaesthetics can be used to stop pain during labour or caesarean sections.

Nerve block

A nerve block involves injecting local anaesthetic around a cluster of nerves that supply a particular part of the body, such as an arm or leg, or a finger or toe. These numb a large area.

Nerve blocks may be used during and after surgery, for example on the hip or knee.

How do I prepare for a local anaesthetic?

All anaesthetics have risks, so talk to your doctor about your options. Discuss any medical conditions or allergies you have. You can also ask about how to manage the pain after the local anaesthetic has worn off, and about any other concerns or worries you may have.

What are the possible complications of having a local anaesthetic?

The most common complication of having a local anaesthetic is pain or bruising on your skin where you had an injection. This is more common in people taking a medicine to stop their blood from clotting, such as aspirin or blood thinners.

Rarely, a local anaesthetic can cause temporary nerve damage. This will cause a part of your body to become weak or numb for some time. More serious complications of local anaesthetics are very rare.