A local anaesthetic is a type of medicine used to temporarily numb a part of your body. Unlike a general anaesthetic, local anaesthetics do not cause the loss of consciousness. When a local anaesthetic takes effect you will feel no pain, but may still sense pressure or movement.
How local anaesthetic works
A local anaesthetic works by blocking the nerves from the affected part of your body, so that pain signals cannot be transmitted to your brain. The numbing effect usually occurs within minutes and may last for a few hours.
Types and uses of local anaesthetic
A local anaesthetic is usually the choice for surgery on small areas of your body, such as minor skin surgery or the extraction of a wisdom tooth. It may also be used with a general anaesthetic to improve pain relief after surgery.
Topical anaesthetics are available as liquids, creams 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.
Epidural and spinal anaesthesia
Epidural and spinal anaesthetics are often used to stop pain during labour or caesarean sections. An epidural block and a spinal block both involve the injection of local anaesthetic into the spine.
A nerve block involves injecting local anaesthetic around a cluster of nerves that supply a particular part of the body, such as the arm or the leg. These numb a large area. Nerve blocks may be used during and after surgery, for example on the hip or knee.
Preparing for a local anaesthetic
All anaesthetics have risks so talk to your doctor beforehand 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.
Last reviewed: December 2017