It could be bacteria, dirt, dust, or other particles that get trapped in the mucus. The nerves transmit a signal to your brain's sneeze center, which in turn sends messages to other body parts.

Sneezing is a reflex that helps expel pollen, dust, and other irritants from your nasal passages. Your brain prevents reflexes in NREM sleep and muscle movements in REM sleep, so you can't sneeze.

Medically reviewed by Alicen Nelson MD, MPH Although the risk is very low, stifling a sneeze can cause a ruptured eardrum, ...