When explaining an illness to a 10-year-old, it is important for the nurse to keep in mind that at this age, children are typically in the concrete operational stage of cognitive development. This means that they are able to think logically and systematically, but they may still have difficulty understanding abstract concepts or ideas. It is therefore important for the nurse to use concrete and specific language when explaining the illness, and to provide concrete examples or visual aids to help the child understand. It is also helpful for the nurse to break down the information into smaller chunks and to provide opportunities for the child to ask questions or clarify any misunderstandings. It is important for the nurse to be patient and to allow the child time to process the information, as this can be a difficult concept for children at this age to grasp.