Ever try to stop a sneeze? Not easy, is it?
Sneezing is a reflex. "When your nose itches you sneeze," just as your knee jerks when a doctor taps it, says allergist William E. Berger, M.D., a past president of the American College of Allergy, Asthma and Immunology. "Closing your eyes when you sneeze is also part of the reflex reaction."
Sneezing may seem simple, but it's more involved than you think. Here's how it works:
Your nose often warns you a sneeze is coming. An irritant makes your nose start to itch or tickle.
Then the part of your brain termed a "sneeze center" sends a message to designated muscles. "The signal from the brain tells our body to sneeze as a means of clearing out the irritating particles," says Dr. Berger.
The chest, abdomen, diaphragm, vocal cords, throat and eyelids join in a certain order to launch a sneeze. Presto -- your nose releases the irritant that's causing that itch. A sneeze propels particles from your nose at a speed of up to 100 miles per hour.
Some particles sneak into your nose in a normal breath. A lot more come from colds or allergies. But the cause of your sneeze could also be bright sunshine.
Strange as it sounds, bright light causes one out of three people to sneeze. Some doctors call them "photics," from the Greek meaning "of light." Photic sneezers can blame their parents -- you inherit this trait.
You may be tempted to stop a sneeze. Don't.
"Holding back a sneeze can cause pressure and lightheadedness. There have actually been reports of people suffering a stroke from the pressure caused by holding back a sneeze," says Dr. Berger, "because it can cause a reduction in circulation by squeezing on the blood vessels."