What Happens to Your Body When You Sneeze?

When your face contorts like this, it's a clue that something big is happening inside. antpkr/Shutterstock

Sneezing is one of the many wonders of the human body, another one of our protective reflexes. When something irritates the inside of our nose — such as dust or pollen — the tiny nerve endings inside our nose send a message to our brain that in turns sends out messages to numerous parts of our body to facilitate the sneeze.

There are a lot of split-second events involved, as this Washington Post graphic suggests. Your chest muscles compress your lungs, which send a burst of air upwards. The throat shuts tight, which then sends the air shooting through your nose at speeds up to 100 mph. And let’s not forget the spray; there are 2,000 to 5,000 bacteria-filled droplets emanating from your nose and mouth when you sneeze. (Needless to say, a tissue or some other form of protection for your nearest and dearest is in order.) Someone with a cold also sneezes quite a bit for the same reason — the swelling in their nasal passages can cause irritation.

It's a fascinating process — so fascinating that it's been the topic of much research, the latest from Lydia Bourouiba, a mathematical physicist from MIT whose exploration was published in the New England Journal of Medicine in 2016. Her work is expansive, but her overall goal is simple: to understand how sneeze droplets (and disease microbes) travel. She breaks down the sneeze in ways you might not want to understand, but you have to admit, this slow-motion video is impressive:

Don't hold it in

Sometimes you feel the urge to sneeze when you're in a meeting or it's the quiet part of a play or concert. You might do your best to stifle the reflex so you don't let loose with a loud explosion.

But it's better to interrupt your coworkers and seatmates than risk some health consequences, say researchers.

A 34-year-old in Leicester in the U.K. ended up rupturing his throat while trying to hold in a forceful sneeze.The man said he felt a "popping" sensation in his neck after pinching his nose and holding his mouth closed to stop a sneeze. The pressure didn't have anywhere to go, so it tore the soft tissue.

The man had to be fed by a tube and eventually made a full recovery. Researchers, who described the case in the journal BMJ Case Reports, said trapping a sneeze can be dangerous and can also result in something as serious as a brain aneurysm.

Not all sneezes are alike

man sneezing
Some people are loud sneezers and others are a bit more refined. Zoriana Zaitseva/Shutterstock

I know all sorts of sneezers. Quiet ones and loud ones. Ones who hold in the sneeze as if there’s a little explosion going on in their head, and the ones who let it rip so loud that the people around them jump. But what’s funny to me is how some people seem to sneeze just once and some people tend to be series sneezers. (Cue "Seinfeld" episode about the appropriate time to say "God bless you.")

Each person is bound to be different. As Dr. Mitchell Grayson, a professor in the division of allergy and clinical immunology at the Medical College of Wisconsin in Milwaukee, explains to Everyday Health: "Some people have bouts of sneezing. It's a neurologic reflex, and it depends on the person. Some people may have 10 to 20 sneezes in a row." It usually depends on the level of irritation in your nose though, because you’ll keep sneezing until you get it out.

I’m sure you’re familiar with the long-standing myth that your eyes will pop out of your head if you sneeze with them open. (David Goldstein, who sat behind me in elementary school, spent the better part of fifth grade trying to sneeze with his eyes open to do just that. What his plan was if his eyes actually did pop out, I do not know.)

The myth begs debunking. Our eyes are firmly attached to our heads, thanks to a group of delicate muscles. They are not, contrary to this popular grade-school myth, going to fall out of our heads if we forget to close our eyelids when we sneeze. So why do our eyes shut tight when we sneeze? It's simply a reflex, much like our leg going up when our knee is tapped. It doesn’t really have a good reason — it just happens. There are those who can sneeze with their eyes open, though I don’t know any personally. (If you're one of the lucky few, please tell us about your experience in the comments below.)

And why the “God bless you” response? There are lots of explanations for this one, the most popular one attributing the phrase to Pope Gregory VII in the sixth century, who would literally bless those who sneezed so that they wouldn’t fall ill with the plague.

I prefer Seinfeld’s response to sneezing in the episode I mentioned above: “If you want to make a person feel better after they sneeze, you shouldn’t say ‘God bless you.' You should say, ‘You’re soooo good-looking.’” Amen to that, Jerry.