Certain body cells make more of a chemical called hypochlorous acid when they're fighting a virus and there's extra salt around, which can be measured with special tools.

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.

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.