"Thin mucus" refers to a watery and less sticky substance that our bodies produce in places like our nose, throat, and lungs. It helps to keep these areas moist and traps dust or germs. Full definition
It helps thin the mucus, making it easier for your body to get rid of it. (drstevenlin.com)
Staying well - hydrated helps thin the mucus in your lungs and sinuses, making it easier for your body to clear the sludgy stuff out of your system — so in addition to lots of water cozy up to soothing herbal teas, hot water with lemon and hot, healthy beverages until the warmer weather returns. (truehealthct.com)
Why: Liquids help by thinning mucus, easing a dry cough, and fending off dehydration due to fever, Heller says. (health.com)