When I was a child, it was said on the playground that holding back a sneeze would make your eyes pop out of their sockets.

It’s the kind of scare tactic that falls somewhere between “when you swallow gum, it stays in your stomach for 10 years” and “if you hit the ground in a dream, you die in real life.” Even at seven years old, I didn’t believe it, and I still have both eyes to prove it.

I’ve been a sneezer my entire adult life, and I always thought I was doing something thoughtful by protecting those around me from my nasal expulsions. When I can’t hold back a sneeze, I usually try to make a noise against my elbow. But I always felt like I was doing some kind of yoga pose wrong: Is it elbow up and upside down? Am I covering my mouth or just making a vague gesture toward my own bicep? But it turns out that, although you’re unlikely to lose your eyes doing so, holding in a sneeze isn’t exactly the safe bet I once thought it was.

“The same physical principles that make sneezing an effective airway defense mechanism can, in unusual circumstances, contribute to injury when the reflex is forcibly interrupted,” says Dr. Qin Liu, a researcher at Washington University in St. Louis. popular science. So how dangerous is it to hold back a sneeze?

A sneeze is meant to go somewhere, not come back to you.

As chaotic and unpredictable as sneezing may seem, it is far from random. According to Liu, sneezing evolved as a defense mechanism: a quick and forceful way to remove irritants, allergens and pathogens from the upper respiratory tract before they can cause any harm. The force behind this is powerful, and for good reason. So how does your body actually generate the force of a sneeze?

Liu offers a vivid (if somewhat terrifying) metaphor for what really happens in the body during a sneeze. The diaphragm and intercostal muscles (located between the ribs) do the main work. “The diaphragm and intercostal muscles work like a gun, while air pressure acts like a bullet,” Liu says.

In a normal sneeze, all that accumulated energy shoots out of the nose and mouth and disperses into the air. But when you block both outlets by pinching your nose and closing your mouth, that pressure has nowhere to go.

“A sneeze is designed as an open pressure release system,” Liu says. “Problems arise when that release pathway is suddenly blocked.” Instead of being fired into the open air, that same force returns to the body itself, to tissues and structures that are not intended to absorb it. If the pressure is strong enough, something gives.

That trapped pressure, Liu explains, can travel to the nasopharynx, sinuses, eustachian tubes, and even the middle ear. In rare cases, it pushes even further, into the deeper tissues of the neck or chest.

What is sneezing?

Dr. Qin Liu, a researcher at Washington University in St. Louis, compares sneezing to firing a gun. Video: What is sneezing? / Cleveland Clinic

None of these structures are built to absorb that type of force. They’re just in the way when the pressure has nowhere to go.

“If those forces exceed the mechanical limits of a particular structure, tissue injury can occur,” Liu says.

The result, according to Liu, can include a ruptured eardrum and barotrauma to the middle ear; Basically, the ear bears the brunt of the pressures it was not designed to withstand.

It can also cause pharyngeal injury, damage to the tissue lining the throat. In rarer cases, the consequences become more serious: cervical emphysema, where air becomes trapped under the skin of the neck, sometimes causing visible swelling, and pneumomediastinum, where air leaks into the space in the chest between the lungs.

For most people, holding in an occasional sneeze won’t land them in the emergency room. But the fact that any of this is possible—that something as common as a sneeze can, in the wrong circumstances, damage the ears, throat, and even chest tissues—says something about how much force our bodies are generating.

When in doubt, let it out.

So holding back a sneeze isn’t doing you any favors. But what’s the best way to control an impending sneeze without turning it into a full-scale microbial spray?

According to Liu, the safest option is simple: let the sneeze happen and contain it with a tissue or sneeze into your elbow.

If letting your sneeze out completely isn’t an option (say you’re mid-sentence in a job interview or giving a eulogy), Liu recommends not blocking both outlets completely. Allowing at least some air to flow through your mouth can relieve some of that pressure buildup.

Liu says there is also a brief opportunity to avoid a sneeze before the reflex fully activates.

“Some people can occasionally interrupt a sneeze during its early stages by removing the triggering stimulus, altering their breathing pattern, pressing their tongue against the roof of their mouth, or applying mild sensory stimulation around the nose or upper lip,” he says. “These approaches can interfere with sensory processing before the reflex reaches full activation.”

But that window is small. “Once the sneezing motor program has been fully activated, voluntary control becomes quite limited,” Liu says. In other words, once the sneeze is in full swing, your body is basically on autopilot.

“Allowing sneezing to occur in a controlled and hygienic manner remains the safest recommendation,” he says.

So there you have it. From now on I’ll let my sneezes happen. My elbow and I have some practice to do.

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