Some people bless you for sneezing because they think it makes your heart stop. Yet this is only a myth. Often, a sneeze starts with a tickling feeling in the nose. Your brain receives a signal from the nerve endings that something is hurting your nasal passages and the brain tells your body to get rid of it.
By taking a deep breath and contracting your chest muscles, your body becomes ready. Your eyelids close, your tongue moves to the roof of your mouth, and your breath whooshes out of your nostrils quickly as the pressure in your lungs rises.
This increased pressure in your chest can change your blood flow, which may alter your heartbeat, delaying it a little. Since the heartbeat comes after a pause, it may be slightly more forceful than your regular heartbeats, which is what may have led people to believe that your heart stops when you sneeze.
There are a number of other myths and superstitions involving sneezing. Some people think that when you sneeze, the soul leaves your body via your nose. Blessing someone is believed to keep the devil from claiming the soul once it has been set free. Others have the opposite view, saying that blessing a person can stop the devil from penetrating their spirit by sneezing.
The custom of wishing someone well when they sneeze dates back hundreds of years. The Greeks would wish each other “long life,” whereas the Romans would say “Jupiter save you” or “salve,” which meant “good health to you.”
Pope Gregory the Great established the custom of saying “God bless you” back in the sixth century. The Pope commanded litanies, processions, and prayers at the time that the bubonic plague was sweeping over Europe. A person who sneezed was instantly blessed in the hopes that they would not actually contract the plague since sneezing was one of the first indicators of the illness.
When someone sneezes, it has become traditional to say “bless you” in English or “gesundheit,” which translates to “good health” in German.