Why do we sneeze?
No, bless you. The primary purpose of a sneeze is straightforward — sneezes help to remove irritants from the nasal passage. These irritants include dust, dirt, pollen, smoke, or anything else that could possibly get stuck in there. Blowing all of that tiny debris out is the best way your body can clear it.
Sometimes sneezes seem to come in pairs or more. Some people have a specific number of sneezes that they produce each time. If someone sneezes three times, every time, their sneezes might not be as powerful as a single-sneezer’s is, and it requires three attempts to get rid of the irritant.
Sneezing also plays an important role in fighting the spread of bacteria when we’re sick. The body’s natural reaction to infection is to produce mucus in an effort to trap the bacteria. Once trapped, it’s time to get rid of it. Sneezing is the most efficient way to expel mucus from the body. It’s also the most efficient way to spread bacteria, so (now more than ever) remember to cover your mouth and nose.
Even when there aren’t irritants or bacteria present, your nose produces mucus to catch potential irritants before they can get to your lungs. Sometimes, through normal production, the nasal passage gets too full and needs to be reset. Whenever you have a random sneeze that seems to be out of nowhere, it’s most likely just to reset your nasal passage.
Sneezing is still somewhat of a mystery, however, as there are some causes that don’t seem to make much sense. About one in four people sneeze when they look into a bright light. This is called a photic sneeze reflex, and it’s an inherited genetic trait. The leading theory is that certain stimulation of the optical nerve causes the same sensation in your brain as irritation in the nose, but the true cause still eludes researchers.