Phlegm is the name given to the excess mucus occurring in and secreted from the respiratory passages, mainly lungs, throat and sinuses. The sticky fluid of the nasal passages is not phlegm. Differing from this scientific view of the Westerners, the Chinese consider it as “congealed moisture” opposing the body’s Qi (or Chi). According to them while Qi, which is “vital energy”, is ‘light and flowing’, phlegm is just the opposite, ‘substantive and stagnating’. From the time of Hippocrates to the nineteenth century, phlegm was one of the four bodily humours (the others being black bile, yellow bile and blood). It was thought that phlegm caused sluggishness and laziness.