Local anaesthetic is a type of painkilling medication that is used to numb areas of the body during some surgical procedures.
The word "anaesthetic" comes from the Greek word meaning the absence or loss of sensation.
Local anaesthetic is different from general anaesthetic which is used for larger operations when a person needs to be unconscious. You stay awake when you have a local anaesthetic.
Read more about other types of anaesthesia.
How does local anaesthetic work?
Local anaesthetic causes a complete loss of feeling to a specific area of your body without making you lose consciousness. It works by blocking the nerves from the affected part of your body so that pain signals cannot reach your brain. You will not be able to feel any pain during the procedure but you may still feel some pressure or movement.
It only takes a few minutes to lose feeling in the area where local anaesthetic is given. The doctor will make sure that the area is fully numb before starting the procedure. It can take a few hours for local anaesthetic to wear off and for full feeling to return. You should be careful not to damage the area during this time. You may be offered painkillers if it's thought that you'll be in pain after the anaesthetic has worn off.
When is local anaesthetic used?
Local anaesthetic is often used by dentists, surgeons and GPs when carrying out minor operations on small areas of the body. For example, local anaesthetic is often used during:
- the removal of a tooth or a filling
- minor skin surgery, such as the removal of moles, warts and verrucas
- some types of eye surgery, such as the removal of cataracts (cloudy areas in the lens of the eye)
- some types of biopsies, such as a needle biopsy, where a tissue sample is removed for examination under a microscope
Local anaesthetic is also sometimes used during more major surgical procedures, such as certain types of brain surgery.
For example, it may be used when a brain tumour is located in the area of the brain that controls speech. As the tumour is being removed, you will need to remain conscious so that you can respond to the surgeon’s instructions. This helps them ensure that your speech is harmed as little as possible during the procedure.
Some creams and ointments that are available over the counter from pharmacists contain local anaesthetic. For example, gels for mouth ulcers sometimes contain small amounts of benzocaine, which numbs the area around the ulcer.
Epidural anaesthetic
Epidural anaesthetic is sometimes used during childbirth to ease the pain of labour or after surgery that has been carried out under general anaesthetic.
An epidural is a type of local anaesthetic that works by blocking the nerve roots from the spinal cord. If a woman decides to have an epidural during childbirth, anaesthetic will be injected into the area below the spinal cord (epidural space). This numbs the lower part of the body so that she does not feel any pain while giving birth.
Read more about epidural anaesthesia.
Regional anaesthetic
This is also known as peripheral nerve block anaesthetic. A nerve block is an injection of local anaesthetic near a nerve to block pain during and after surgery. This may be used for an operation on a hand, arm or leg so that it can be carried out without the need for a general anaesthetic.
An ultrasound scan is often used to pinpoint the correct nerve, and the injection should not be painful.
The block usually takes full effect in about 30 minutes and it may be used in combination with general anaesthetic.
A screen is used during any operation that follows so that you do not see the surgery taking place.
Side effects
There may be temporary side effects after local anaesthetic is used, but there should be no long-lasting problems.
Side effects can include:
- a numb tongue
- dizziness
- blurred vision
- twitching muscles
If you have any of these symptoms, tell the doctor who administered the local anaesthetic. In rare cases, these symptoms can progress to more serious complications such as seizures (fits) or cardiac arrest (when the heart stops pumping blood around the body).
