When you need to have a procedure in hospital it can be a very stressful and scary time for you. Understanding what hospital procedures do and explaining them to you is not easy for parents. You might feel anxious when the nurse needs to use a needle to take a blood sample. You might worry when you are asked to go into an MRI machine or have a general anaesthetic. The WWCIH charity makes video clips suitable for you and your parents prepare for hospital and answer some questions starting with What? and Why?