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

Clear, bubbly phlegm does not typically indicate a problem. However, coughing up large amounts could indicate an underlying health issue, such as fluid in the lungs. Phlegm, or sputum, is a type of ...

It’s never any fun feeling under the weather, but when a common cold is paired with excess phlegm, it makes matters even worse. This can lead to irritating symptoms, such as coughing, a sore throat, ...