/ Science / Health and Body / Ask a Doctor: Cite Why do we sneeze? We sneeze to clear our breathing passages. We all have a natural reflex to sneeze whenever a small foreign substance enters our airways. So don’t hold back your sneezes-let ‘em rip! What happens when my foot falls asleep? Q&A about the Body Download Poptropica and play for free!Explore a limitless universe of uncharted islands See also: Why do people sleep?