phlegm

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.

In this study, experts engineered a living material resembling natural sputum, or phlegm, from CF patients that can grow 3D polymicrobial biofilms in a controlled manner, resembling those found in the CF lung.