Other forms: sneezing; sneezed; sneezes
When you sneeze, you blow air forcefully (and involuntarily) out of your nose and mouth, possibly while making a sound that might be spelled "achoo!" Allergies, pepper, and dust are all famous for making people sneeze.
Behind every sneeze is some kind of irritant, a foreign substance that bothers the mucous membranes inside your nose. Pollen, cat dander, and the inflammation of your nose caused by a cold virus can all cause a sneeze (or several sneezes). When you sneeze, muscles in your face, neck, and chest contract reflexively. In rare cases, very bright lights or eating a large meal can make people sneeze. Go figure!