This is usually done under general anaesthesia, where you will be completely asleep and unaware of what is happening. Having a general anaesthetic is safer than driving a car.
The current risk is quoted at 1 in 250,000 chance of something going wrong. It is very important to stop smoking four weeks before an operation, and for four weeks after. You should also get your blood pressure checked by your GP. If your blood pressure is high you will need medication to bring it under control before an operation. If you have a cold or are feeling unwell the day before an operation it is better to postpone it until you are recovered. An experienced anaesthetist will anaesthetise and monitor you during your operation. Trained staff is on hand through every step of your operation and recovery. Good results and enhanced safety come from having an experienced team.