Some people believe that your heart stops when you sneeze, which is why they bless you. This is just a myth however.A sneeze usually begins with a tickling sensation in your nose. The nerve endings send a message to your brain that there is something irritating your nasal passages, and the brain signals your body to get rid of it. Your body prepares itself by taking a deep breath and tightening your chest muscles. As the pressure in your lungs increases, your eyes close, your tongue goes to the roof of your mouth and your breath whooshes out really fast from your nose.
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 lead people to believe that your heart stops when you sneeze.There are several other beliefs and superstitions that are linked to sneezing. Some people believe that a sneeze causes the soul to leave the body through the nose. Saying "bless you" is supposed to prevent the devil from claiming the freed soul. Others believe the opposite: that the devil enters the soul when a person sneezes, and blessing them can prevent it.
So why do they bless you?
Wishing a person well after they sneeze is a practice that originated hundreds of years ago. The ancient Romans would say "Jupiter preserve you" or "salve," which meant "good health to you," and the Greeks would wish each other "long life."The practice of saying "God bless you" was first started by Pope Gregory the Great, way back in the sixth century. The bubonic plague was sweeping across Europe at the time, and the Pope ordered litanies, processions, and prayers to help combat the plague. Since sneezing was one of the first symptoms of the disease, a person who sneezed was blessed immediately in the hopes that they would not actually get the plague.
Today, it has become customary for people to say "bless you" in English or "gesundheit," meaning "good health" in German, when a person sneezes.