Mucus is a thin, slippery fluid that lines the nose, throat, and other passages to trap dust and germs. Phlegm is a thicker type of mucus produced in the lungs to catch and remove harmful particles ...

Mucus consists mainly of water and a gel-forming molecule called mucin. The body uses mucus to protect tissues, remove particles, and prevent infections. Mucus is essential for the functioning of many ...

When you're sick you'll often produce more phlegm, and might notice it's thicker or a different color: white, green, yellow or maybe even brown. We all produce mucus, even when healthy. Mucus is a ...