Sneezing, also known by its medical term, sternutation, is an involuntary, powerful expulsion of air through the nose and mouth. It can be triggered by irritants in the nasal passage or throat, allergies, or even a common cold. Interestingly, some people sneeze in response to bright light—a condition called photic sneezing, formally known as autosomal dominant compelling helio ophthalmic outburst syndrome, or simply ACHOO syndrome.

When someone sneezes, the polite response is usually "bless you" or "God bless you." This custom is so ingrained that not responding can create a socially awkward moment, unlike with other bodily functions like coughing. Sneezes often draw multiple blessings from those nearby, reinforcing this social expectation. But why do we say "bless you" in response to a sneeze?

A Prayer for Protection

Before modern medicine improved life expectancy, which in 1900 was a mere 32 years globally (and doubled by 2021), illnesses like the bubonic plague and influenza could decimate entire communities. In such times, a sneeze could be a sign of impending illness or death, prompting people to offer prayers of protection.

The origin of saying "God bless you" after a sneeze is often linked to Pope Gregory I, also known as Pope Gregory the Great, during a plague outbreak in the sixth century. It was believed that sneezing could be a harbinger of death. However, the practice of acknowledging a sneeze with a verbal response predates Pope Gregory. Roman philosopher Pliny the Elder mentioned it in his 77 CE work Natural History, noting that even the notoriously unsociable Emperor Tiberius Caesar insisted on being saluted after sneezing. By Pliny's time, the custom was already old enough for its original meaning to be forgotten.

One popular theory is that ancient people believed sneezing allowed evil spirits to enter the body or that the act temporarily expelled the soul, leaving it vulnerable. There was also a belief that the heart stopped during a sneeze. In all these cases, saying "God bless you" was a way to invoke divine protection for the sneezer's soul and guard them—and those around them—from harm.

Sneeze Etiquette Around the World

Today, saying "bless you" remains the norm in the U.S., the U.K., and other English-speaking countries, largely due to colonial influence. However, different cultures have their own sneeze responses. In many European countries, the response is typically a version of "health," such as "salud" in Spanish, "salute" in Italian, and "gesundheit" in German-speaking regions (a term that is also used in the U.S. due to German immigration). In some Latin American countries, multiple sneezes are met with additional blessings: "salud" for the first sneeze, "dinero" (money) for the second, and "amor" (love) for the third.

In contrast, sneezing in East Asian cultures typically doesn't receive a response unless it's excessive, in which case people might inquire about the sneezer’s health.

The custom of responding to a sneeze may have ancient roots, but it continues to be an enduring practice, with variations across different cultures and regions.

Credit: Kristina Wright