Because you're hearing "Bless You" wrong, or they heard "Bless You" wrong and are saying "Blush You" because that's what they think you say when someone sneezes.
People say "Bless You" because there was an old belief that your soul could slip out (or a demon could slip in) of your nose when you sneeze. The superstition is mostly gone, but the practice stuck.
Because when you sneeze the sound you make is "SNEEZE!" ^No, it really isn't. I've not heard one person say "SNEEZE" when they sneeze, ever in my life. I've heard people say "Achoo", "Atishoo" and other ones, but never "SNEEZE".
they say haliio ling
some people say "Achoo" some people say "Hachoo" it depends on who you are.
they say Kai lon unga.
they say bless you because when you sneeze your heart stops's there thanking god that you did not die
It's a sneeze-they are not speaking.
People with all color do blush.
All people blush.
Make up blush is called in Spanish Rubor
people used to think that if you sneezed you sneezed out your soul and they say bless you so the devil wont get it.
No, people can not sneeze out water and oil.
The same way people today sneeze.