We all sneeze now and again. 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.
Just a few of the muscles used in a sneeze include those of the stomach, chest, vocal cords, throat, and eyelids. And they all work seamlessly together to blast particles out of the nose and mouth.
“Did you know you always close your eyes when you sneeze?”
Colds and allergies often make us sneeze. But there are also some other, less familiar, reasons.
Bright Light
One in three to four people is a ‘photic sneezer’. This means they sneeze in response to sudden exposure to bright light. This is an inherited trait.
When a photic sneezer is suddenly exposed to 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!
Dust
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 defence against allergens is the nose—which is why we often sneeze when dust or pollen first enters the nasal passages.
Cold Air
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 become enlarged, bringing on a sneeze.
Pepper2
White, black, red and green peppercorns all contain a chemical called piperine, which irritates the nose and causes sneeze.