When English speakers hear achoo, they usually respond with either gesundheit or God bless you. Gesundheit was borrowed from German, where it literally means "health"; it was formed by a combination of gesund ("healthy") and -heit ("-hood"). Wishing a person good health when they sneezed was traditionally believed to forestall the illness that a sneeze often portends. God bless you had a similar purpose, albeit with more divine weight to the well-wishing. It was once believed that the soul could exit the body during a sneeze, causing ill health, so folks said "God bless you" to ward off this danger. Gesundheit, at one time, also served as a toast when drinking (much like its English counterpart, "to your health"), but this usage is now mostly obsolete.