Evidence status: DOCUMENTED custom — exact origin unknown
Someone coughs and we may ask if they are all right.
Someone hiccups and we usually ignore it.
But let them sneeze and complete strangers may immediately offer a blessing.
Why does one ordinary bodily reflex receive its own tiny ceremony?
The Short Answer
People have treated sneezing as significant for thousands of years, and many cultures developed verbal responses wishing the sneezer health, long life or divine protection.
The English “God bless you” has often been attributed to Pope Gregory I during a plague outbreak in Rome around AD 590. According to the familiar story, sneezing might signal dangerous illness, so Gregory encouraged prayers for anyone who sneezed.
That explanation is possible, but it is not securely demonstrated as the moment the custom began. Ancient Greeks and Romans were already interpreting sneezes as omens and responding to them long before Gregory.
The safest conclusion is that “bless you” grew from a much older human tendency to treat the sudden, uncontrollable sneeze as a moment requiring protection or good wishes.
What We Know
Sneezing attracted attention in the ancient world.
A sneeze could be interpreted as an omen — sometimes favourable, sometimes threatening.
The important point is that people did not always view it as a meaningless biological reflex.
It might appear to reveal something about:
health,
the gods,
fortune,
or an unseen supernatural world.
That makes the later habit of responding verbally much easier to understand.
The Library of Congress notes that different cultures developed responses ranging from blessings to wishes for health and long life. Modern German Gesundheit, for example, simply means “health”. Spanish salud works in much the same way.
How It Became a Habit
Sneezing has three qualities that make ritual responses surprisingly likely.
It is sudden.
It is involuntary.
And it momentarily interrupts whatever everyone nearby is doing.
That gives the group a small social problem.
Something happened.
Do we ignore it?
Comment on it?
Check the person is well?
A short verbal response solves the problem instantly.
Over centuries, what may once have been prayer or protection gradually became politeness.
Today an English speaker may say “bless you” with no religious intention whatsoever.
The words survive after much of the belief behind them has disappeared.
The Story Everyone Tells
The most famous explanation involves Pope Gregory the Great.
Gregory became pope in 590 during a devastating epidemic in Rome.
According to later tradition, he encouraged prayers and blessings, and sneezing became associated with imminent illness.
Hence:
someone sneezes,
another person says “God bless you”,
and the blessing protects the sneezer from plague.
The story is endlessly repeated.
The Library of Congress lists it as one traditional explanation rather than established fact.
What the Evidence Actually Says
The Gregory story has a chronological weakness.
People were assigning supernatural meaning to sneezing long before the sixth century.
That means Gregory cannot plausibly have invented the broader human practice of reacting ritualistically to a sneeze.
Other popular explanations are even harder to prove.
One says people believed the soul could accidentally escape through the nose during a sneeze.
Another says the sneeze expelled evil spirits and the blessing prevented them from returning.
These are genuine pieces of later folklore, but none can be identified as the original explanation.
There is also a modern myth:
the heart supposedly stops when a person sneezes.
It does not.
Sneezing changes pressure in the chest and can temporarily affect heart rhythm, which may produce the sensation of a skipped beat, but the heart does not simply stop.
So:
DOCUMENTED: Sneezes have been treated as omens or significant events since antiquity.
DOCUMENTED: Many cultures developed conventional verbal responses to sneezing.
PLAUSIBLE: Christian blessing formulas and fear of disease helped shape the English response.
FOLKLORE: Gregory I cannot be securely credited with inventing the custom.
FOLKLORE: A sneeze does not make the heart stop.
UNKNOWN: There is no single demonstrated origin for saying “bless you”.
Different Elsewhere
English chose blessing.
German chose health.
Spanish chose health too.
Other languages use wishes for long life or wellbeing.
And some cultures traditionally say nothing at all.
That variation tells us something useful.
There is no natural human rule requiring a response to a sneeze.
The sneeze is biological.
What comes afterwards is cultural.
Why It Stuck
Because it takes less than a second.
Someone sneezes.
Someone says “bless you”.
The tiny exchange acknowledges another person without demanding conversation.
An ancient omen may have gradually become one of the smallest acts of everyday politeness.
Related Curiosities
Why Do Children Leave Teeth for the Tooth Fairy?
Why Do We Cross Our Fingers for Luck?
Why Do We Throw Salt Over Our Shoulder?
Why Are Black Cats Considered Unlucky?
Sources & Further Reading
Library of Congress — “Does your heart stop when you sneeze?” — discussion of sneeze folklore, the Gregory story and responses in different cultures.
Library of Congress — sneeze physiology — explains why the heart may feel as though it skips a beat without actually stopping.
Last checked: 19 September 2026