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.

If the cough occurs with other symptoms like fever, shortness of breath, bloody phlegm, or weight loss, they recommend getting evaluated sooner.

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.