Gesundheit! Why Do We Sneeze?
Photo Credit: tetmc /

How a Tickle in the Nose Leads to a Full-Body Spasm

Sneezing is a universal reaction, something everyone will experience — especially during allergy season. Some people sneeze loudly, and some sneeze gently, but every nose will go through the famous response at one time or another.

If you’ve ever wondered just what is prompting your nose to send out a sneeze, you’re not alone. Researchers have been looking more deeply into how sneezes work, when they happen, and why they’re important. You might be surprised at some of the facts they’ve uncovered.

The Anatomy of a Sneeze

A sneeze is a quick and intense event, but there’s more going on than you might imagine. It begins with a tickle that recruits more muscles in the span of a second or two.


Some sort of irritation in the nostrils initiates a sneeze, and when the nerve endings pick up on that irritation, they relay a message to your brain to rid your body of the irritating substance.

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Before you can sneeze to expel the irritation, you have to take a deep breath to get the force to push out the invaders. You’ll need to take a deep breath, as the tickling in your nose continues.

Increase in Pressure

As you take in a very deep breath, your chest muscles, abdominal muscles, diaphragm, and muscles in the back of your throat tighten, increasing the pressure in your lungs. This momentary build-up causes your eyes to close and tongue to press on the roof of your mouth in anticipation.

Change in Blood Flow

As pressure increases, your blood can slow, and your heart may even skip a beat. This once led people to suspect that the heart stops when you sneeze (but that doesn’t happen).

Strong Exhalation

As soon as enough pressure has built up with a lungful of air, your throat muscles quickly relax, and your body sends the air out rapidly — usually with a burst of saliva if you don’t keep your mouth closed.

Once a sneeze begins, it’s nearly impossible to control. Not only are they loud, but sneezes can travel up to 100 miles per hour, and the spray can travel over five feet.

What Can Cause a Sneeze?

Sneezing is a universal reflex, but can be a very individual reaction. Some people sneeze often and at seemingly strange times, while others are only prone to sneezing at particular events.

It all comes down to your own nerve pathways: signals can take different paths to the brain, so different people can experience different sneeze triggers. Some of the most common include:

  • Bright light. Up to 35 percent of people sneeze when they’re suddenly exposed to bright light. This is known as photic sneezing, or the ACHOO syndrome, and is an inherited trait.
  • Eyebrow plucking. Triggering certain facial nerves can lead to sudden sneezing, including those under the eyebrow hairs.
  • Exercise. Not everyone will sneeze during exercise, but for some people, a heavy workout will dry up nasal passages, which causes the nose to drip and irritate the nose until a sneeze begins.
  • Dust. Certainly one of the most common sneeze triggers, a noseful of dust can bring on a violent reaction before you know it. Common household dust is the usual suspect, but spice dust (think black pepper or cayenne) can bring about the tickle, too.
  • Swelling. Viruses lead to inflammation, so it’s not uncommon to sneeze often and repeatedly when you’re fighting a cold. The virus has planted in the tender lining of the nostrils, where it causes the tissues to swell and become extra sensitive.
  • Allergens. Pollen, pet dander, and other airborne irritants can wreak havoc on your nasal passages. Like dust and viruses, the contaminating particles cause swelling and irritation.

Allergies or Illness?

Since so many things can cause a sneeze, it’s not always easy to tell if it’s something worth worrying about. Sneezing isn’t bad for your body — in fact, it’s how your body protects itself from invasive illness — but it can hint at a deeper issue that could set you back for a while.

A cold or flu virus can attack your mucus membranes (like the tissues in your nostrils and throat), leaving them dry, overworked, or just plain irritated. Sneezing is a natural reaction, but you can get over-the-counter medicine to control the violent sinus activity, if need be.

Just remember, once the sneeze is on its way out, it’s far better to let it continue than to try to stifle it: although it’s fairly rare, stopping a sneeze mid-sneeze can lead to burst blood vessels in the eyes, ruptured ear drums, and problems with the diaphragm.

Do Your Part to Stop the Spread

Sneezes are your body’s way of “rebooting” the nasal passages, so the tiny hairs (known as cilia) are better able to trap unhealthy particles before they have a chance to infect your respiratory system.

However, a single sneeze can send over 100,000 germs into the air, so covering your nose and mouth is very important to stop the spread of illness and disease. Sneezing into a cloth or towel is the ideal option, but if you find yourself without a hanky, use the crook of your elbow to trap the germs.