Phlegm is a “liquid secreted by the mucous membranes of mammals” that contains lipids, glycoproteins, and immunoglobulins, among others [1]. It serves several purposes for the body, including keeping tissue surfaces moist to prevent them from drying and cracking [2]. It also traps bacteria and other harmful invaders before they enter the body and cause infection [2]. The color of phlegm may also hint at different conditions. For example, if your phlegm is white or…