phlegm

In theory, each ingredient plays a role: one dries secretions, another loosens phlegm, a third dulls the cough reflex.

She said Hannah's reaction "happened quickly" and she was coughing up phlegm.

The bacterium that causes tuberculosis glows yellow in this phlegm sample; in orange are possible immune cells from the lung.

Many infections involve dry coughs that don't produce phlegm at all.

Take humoral theory: In the Middle Ages, the body was thought to consist of four liquid components called humors—blood, yellow bile, black bile, and phlegm.