Your nose and breathing tubes have special cells that make a natural cleaning chemical to kill viruses when you get sick.

Cells in your breathing tubes make a natural cleaning chemical that kills viruses when they try to infect you.

When you get a virus, your breathing cells need a certain chemical (chloride) to make a germ-fighting acid. If there's not enough of this chemical, your body might not fight off the virus as well.

Rinsing your nose with salt water gives your nose cells what they need to make a natural germ-fighting chemical, which helps your body fight off viruses better.

Salty water might help your body's cells fight off viruses better by boosting natural defenses, which could explain why saline treatments work in some medical trials, but more research is needed to be sure.