Ever Wondered Why You Sneeze? The Surprising Science Behind Every “Achoo!”

Achooo! We all do it, right?

Sometimes loudly, sometimes in a stream of three or four in a row. Yes, sneezing is a very common thing.

But it isn’t just a reflex, it’s a moment that draws attention, invites reactions (If you have sneezed in the lift, that too without covering it!), and even carries cultural meaning.

In some cultures, a sneeze is seen as inauspicious, people take it as a warning and pause before taking a step outside. Sometimes when people are discussing a good proposal and if someone sneezes? They might even reconsider that!  Isn’t it? In others, it’s followed by a quick “Bless you!”, a habit that dates back to ancient times when sneezing was thought to release the soul or welcome illness. Whether it’s superstition or kindness, a simple sneeze commonly creates a bonding/relationship.

But beyond the social meaning, sneezing is your body’s natural defense mechanism, it is a fast, powerful way to clear out irritants and protect your respiratory system.

Any of you, have you ever paused your sneeze in its mid way and wondered, “Why does this even happen?”

So, What Is a Sneeze, Exactly?

A sneeze is your body’s way of forcefully expelling irritants from your nose and sinuses. It begins with a signal from your nose to your brain that something like dust, pollen, smoke, or even a strong perfume that doesn’t belong is present.

Within that fraction of a second you put one big “Achooo”, here’s what happens:

• Your diaphragm and chest muscles contract suddenly.
• Your vocal cords close.
• You inhale deeply and then…
• ACHOO! The air shoots out at up to 100 miles per hour(!), blasting out whatever was bothering your nasal passages.

Yes, it’s a powerful and fascinating built-in defense mechanism designed to protect your body from unwanted invaders.

After the ‘What’, next comes the ‘Why’! Now, let us see, why do we sneeze? The common triggers include both physical and environmental like Allergens(Pollen, pet dander, mold, and dust mites), Infections (Colds, flu, or sinus infections), Strong smells (Perfume, cleaning products, or smoke), Sudden temperature changes (Going from warm to cold air), and Pepper and spices (Even just inhaling the aroma).

Yet another trigger for sneezing is Bright light. Surprised? I heard this for the first time! Yes, that’s a thing and it has a name! “Photic Sneeze Reflex”? Ever stepped into sunlight and sneezed immediately? You’re not alone. There are around 1 in 3 people experiencing the photic sneeze reflex, an inherited quirk where bright light triggers a sneeze. It’s harmless, a bit funny, and still a mystery. Scientists believe it might be due to crossed nerve signals between your eye and nose responses. Maybe, not knowing the name, we might have experienced this!

Have you ever tried to stop a sneeze? (When some auspicious thing happens and you get the symptom of a sneeze, how much you struggled to stop!) Succeeded? No, because sneezing is a reflex, which means it’s automatic. Once it starts, your body goes through a series of lightning-fast steps (mentioned above!) that are nearly impossible to interrupt. That’s why you usually can’t stop sneezing halfway!

Another interesting thing about sneezing is you can’t sneeze with your eyes open, have you noticed that? Your body instinctively closes your eyes to protect them from the pressure.

Though, most sneezing is harmless,  if it is frequent and chronic or it is accompanied by itchy eyes, runny nose, or fatigue or if it disturbs your daily life, then…it could signal an allergy, sinus condition, or respiratory infection. Sneezing with a fever, body aches, or green mucus may point to something more serious like the flu or a sinus infection. If sneezing lasts weeks or worsens over time, it’s worth checking in with a doctor or allergist.

One of my friends is having issues with continuous sneezing. Once she starts she cannot control but she is taking all precautionary measures to prevent sneezing by managing the triggers. Here’s how:(in her own words!)

• Identify allergens and avoid exposure when possible
• Use a saline nasal spray to keep your nose moist and clear
• Keep windows closed during high pollen seasons
• Vacuum and dust regularly
• Use an air purifier in your home
• Treat allergies with antihistamines if needed (check with your doctor)

One Last Thing, but a very important one: Cover That Sneeze!

Sneezing may be your body’s defense system, but it can also spread germs fast. Always:

• Sneeze into a tissue or the inside of your elbow
• Wash your hands afterward
• Avoid sneezing into your hands or into the air(Have you ever experienced this, travelling in an AC vehicle and one of your friends puts a big ACHOOO in the air, that too when he/she is having a severe cold and cough!)

So the next time you sneeze unexpectedly in a quiet room, just remember, your body isn’t trying to embarrass you. It’s working hard to keep your airways clean and your system protected.