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

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 ...

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 ...

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 ...

Phlegm is a form of respiratory mucus produced by the lungs. The airways between the larynx and the respiratory bronchioles are lined by columnar epithelium over which an airway surface liquid (ASL) ...