A medication that causes the loss of sensation by blocking the nerves to the brain. General anaesthetic: A type of medication that is used to send you to sleep during surgery. This means you are unaware of the surgery, and you don’t move or feel pain. Local anaesthetic: A type of medication used to numb areas of the body, without making you lose consciousness (without sending you to sleep). You may be able to feel some pressure and movement, but not pain.