Phlegm. Mucus. Sputum. These are different names for the slimy, slippery stuff that flows out when you cough, sneeze, or sniffle. This gunk is your body’s defense weapon against infectious microbes ...

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 ...

When you're sick you'll often produce more phlegm, and might notice it's thicker or a different color: white, green, yellow or maybe even brown. We all produce mucus, even when healthy. Mucus is a ...

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 ...