Mucus isn't exactly something people give much thought to — until they're sick and dealing with a constantly runny nose. But mucus is actually an important part of a healthy immune system, according ...

Your body naturally makes mucus to protect organs like lungs and eyes. But infections, allergies and pollution can boost mucus production. Know what it does, when to worry and how to ease discomfort.

Black mucus is rare. It can be the sign of a fungal infection, or exposure to pollutants such as coal, dust or cigarette ...

Americans are weathering the worst flu season in years, as a number of other respiratory illnesses circulate too, such as COVID-19, RSV and the common cold. A telltale sign you’re getting sick is ...

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. Subscribe to our newsletter for the latest sci-tech ...

Q: When children are sick, why does their nasal discharge turn green? A: The presence of immune cells that fight infections, as well as disease-causing germs themselves, alter mucus color as an ...

NEW YORK (Reuters Health) - Confirming widespread beliefs by doctors and parents alike, the color of phlegm coughed up by people is indeed a good indicator of whether that person has a bacterial ...

The color of the phlegm from patients with the lung disease bronchiectasis can indicate the degree of inflammation in their lungs and predict their future outcomes, according to new research presented ...