Usually when you sneeze, you are trying to get rid of an irritation or harmful object in the air passage of your nose. Sneezing is a reflex action, an automatic reaction of your body without your controlling or willing it.
The irritation stimulates the nerve cells in your nose to send a message to your brain, saying, “Get rid of the irritation!” Your brain then sends another message to the breathing muscles of your ribs and diaphragm and “Ah choo!” Out goes the troublesome irritation with the sneeze. But because disease-carrying germs can be expelled with each sneeze, you should cover your mouth and nose.
Droplets from a sneeze have been measured traveling at the amazing speed of over 103 miles per hour!