They make sure the person is not in pain. To do this they use lots of different medicines. Anaesthetists also help to make the pain better after the operation.
Before an operation the anaesthetists chat to the patient. They find out what care the patient needs. They will also answer any questions the patient has!
They will give the patient a local or a general anaesthetic. They then keep an eye on the patient's heart rate and blood pressure. They also check their breathing and temperature.
After the operation they make sure the patient has pain medication and enough fluid in their body.
You'll find anaesthetists in operating theatres and hospital wards.