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 ...

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

People often dismiss a cough as a minor ailment, but sometimes it can be a sign of an underlying problem, especially when ...

Even if it is kind of gross when you're full of it and wrestling with it, phlegm actually serves a useful purpose: The thick, sludgy substance—made up of mostly water, salt, and antibodies—is designed ...

Hearing others coughing and choking is one of the annoying things in life, but learning to listen to your cough can sometimes ...

Healthy phlegm is usually clear and runny, but many different health conditions can change the consistency or color. Phlegm, also called sputum, is mucus produced by your lungs that helps protect your ...

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their ...