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 ...

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

Although mucus and phlegm are related terms, they don't mean exactly the same thing. Karl Tapales via Getty Images Most people are all too familiar with the icky, uncomfortable feeling of having mucus ...

Mucus is a slippery, protective substance that keeps your airways, throat, and digestive tract moist, trapping and clearing out dust, allergens, and germs to help protect against irritation and ...

Mucus production is natural. However, overproduction of mucus in the throat can lead to long-term coughing and throat irritation. Certain conditions and factors can lead to an excess of mucus, such as ...

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 ...

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 ...