A sneeze can be caused by dust allergies, hayfever or viral infections such as the common cold and flu. It's basically a sudden, energetic, involuntary burst of air through the nose and mouth that is caused by the mucus membranes of the nose or throat being irritated.
What happens is, just before the big sneeze, the vocal chords close together, the air in the chest becomes compressed, and then the chords are suddenly separated by the blast of air.
Did you know?
As many as 40,000 droplets fly out of our nose and mouth at speeds greater than 200 miles per hour when we sneeze.
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