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 ...

Coughing up white mucus can be a sign of an upper respiratory infection or chronic conditions like COPD. Viral infections that cause white mucus cannot be treated with antibiotics, so focus on rest ...

Mucus is a normal part of the lungs. But smoking and other issues can cause too much mucus to collect there. (Photo Credit: iStock/Getty Images) Your body makes about a liter (approximately 1 quart) ...

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 ...