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.

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

Salt's ability to fight viruses depends on how chloride moves inside cells, not sodium. When chloride movement is blocked, salt can't stop viruses, but blocking sodium movement doesn't change salt's virus-fighting power.

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.

Salt might help fight viruses like coronaviruses in lab tests, and this could be why people feel better when they use salt-based treatments.