Why do we sneeze?

Dear Dr. Cory:

Why do we sneeze?

Alison Smith Edgeley, North Dakota

Dear Alison:

Sneezing is a protective action, or a reflex. We do it without thinking. When something is irritating the inside of the nose or upper airways, we sneeze. Things like dust, dirt, smoke, and pollen can cause us to sneeze. Sneezing helps to keep those particles, along with viruses and bacteria, out of the nose and lungs.

When something irritates your nose, a signal is sent to the brain. The brain tells the lungs to take a deep breath. Then your chest muscles squeeze tight, forcing the air out of the lungs and through the nose and mouth. This blast of air, at speeds up to 100 miles per hour, helps clean out your nose. A sneeze is your nose's way of coughing!