What makes us sneeze?

Cold & Flu What makes us sneeze

What makes us sneeze?

We all sneeze now and again. In fact, even newborn babies sneeze within moments of birth to clear out their noses.1 , Sneezing is considered to be a reflex – a normal, uncontrollable response to irritation or tickling inside the nose. It is also the body’s way of getting rid of nasal irritants, like dust.

When the inside of your nose is irritated, the brain sends out messages to various muscles throughout the body, which work together to produce the complex sneeze.2

Just a few of the muscles used in a sneeze include those of the stomach, chest, vocal cords, throat, and eyelids. And when they work seamlessly together they blast particles out of the nose at up to 100 miles per hour!3

“Did you know you always close your eyes when you sneeze?3”

Colds and allergies  often make us sneeze. But there are also some other, less familiar, reasons.

Bright Light

One in three people is a ‘photic sneezer’.3,4 This means they sneeze in response to sudden exposure to bright sunlight. This can be an inherited trait; however, most people have some sensitivity to light triggering a sneeze.3

When a photic sneezer goes into sudden bright light, scientists believe that the nerves in the eyes that sense light become active, and start to send signals to the brain, saying “Light!”. However, sometimes the facial nerves that go to the nose also become active. When this happens, the brain mistakes the light signal for an irritant in the nose!4


Dust, as well as mould, pollen and other allergens can make us sneeze. Allergies are an immune reaction to substances that are often harmless. The body then attacks these substances in order to try to get rid of them. One of the first lines of defense against allergens is the nose—which is why we often sneeze when dust or pollen first enters the nasal passages.

Cold Air3

A sudden blast of cold air—either from leaving a heated building and stepping into the cold outdoors, or going into a cool building from a hot summer day—can trigger a sneeze. This happens because the sudden blast of cold air causes the membranes in the nose to suddenly contract, bringing on a sneeze.


White, black, red and green peppercorns all contain a chemical called piperine, which irritates the nose and causes sneeze.  Other chemicals in foods may do the same thing. For example, mint gum is a sneeze trigger for some people.



  1. Care of the newborn. Operational Medicine. Bureau of Medicine and Surgery, Department of the Navy.
  2. Why do we sneeze? Scientific American. April 2000. Available at http://www.scientificamerican.com/article.cfm?id=why-do-we-sneeze
  3. What makes me sneeze? Dowshen, S., MD. KidsHealth.org. http://kidshealth.org/kid/talk/qa/sneeze.html
  4. Looking at the sun can trigger a sneeze. Schrock, K. Scientific American January 10, 2008. http://www.scientificamerican.com/article.cfm?id=looking-at-the-sun-can-trigger-a-sneeze  .