Why do we say bless you after a sneeze?

 

The phrase is used to wish someone good health after they sneeze.

One theory is that the phrase originated during the bubonic plague when sneezing was a symptom of the disease. Saying "bless you" was a way to wish someone good health in the hopes that they would not contract the disease. Other theories suggest that the phrase originated from a time when people believed that sneezing was the body's way of expelling evil spirits. Saying "bless you" was a way to protect the person from these evil spirits.