General anaesthesia is a state of controlled unconsciousness during which you feel nothing. You will have no memory of what happens while you are anaesthetised. A general anaesthetic is required for a very wide range of operations. This includes most major operations on the heart, lungs or in the abdomen, and many operations on the brain or the major arteries. Anaesthetic drugs are injected into a vein, or anaesthetic gases are given to you to breathe. These drugs stop the brain from responding to sensory messages travelling from nerves in the body. Anaesthetic unconsciousness is different from a natural sleep. You cannot be woken from an anaesthetic until the drugs are stopped and their effects wear off. While you are unconscious, the team in theatre look after you with great care. Your anaesthetist stays near to you all the time.