How do anaesthetics work?

Having a tooth extracted or drilled may not be pleasant but-thanks to anaesthetics-at least it’s not painful. These drugs also prevent pain in surgical operations. We feel pain because electrical signals flash along the nerves in our body from the part that hurts to the brain. Anaesthetics interfere with the nerves so that these pain signals are locked. A general anaesthetic renders the whole body painless (and temporarily unconscious), while a local anaesthetic affects only the part that hurts and leaves the patient conscious.