TCM treatment is based on “identifying the ailment before curing”. To treat a disease, one must first understand its symptoms before applying medication. Autumn and winter is the peak period for upper respiratory tract ailments and coughing is one of their symptoms. We can know the symptoms and features of coughs.

Previously, we explain the time, frequency, nature and sound of the coughing, and the related factors that worsen the symptoms. Now, we discuss and learn about an important factor of coughing – phlegm – by analysing the intensity of its colour, its viscosity, quantity and taste.

Coughing with a small amount of phlegm is mostly dry-heat. The symptoms of dry-heat invading the lungs are dry coughs, no phlegm or small amount of stringy, sticky phlegm or blood streaks in the phlegm. The symptoms of liver-fire invading the lungs are occasional reflexive coughing, dry throat, frequent sensation of the throat being clogged by phlegm, small quantity of sticky phlegm, or stringy phlegm. If the lungs have weak yin, there will be dry coughing with a small volume of sticky, white phlegm or blood in the phlegm. Coughing with a large amount of phlegm is wet-phlegm coughing. Coughing with symptoms of phlegm-wetness deposited in the lungs are repeated coughing, large quantities of phlegm, coughing due to the presence of phlegm, and coughing stops when phlegm is expelled. The phlegm is sticky, viscous, and is white or grey in colour. Coughing with symptoms of phlegm-heat depressing the lungs are heavy breathing or rattling in the throat due to the presence of phlegm, copious amounts of phlegm, thick phlegm, yellow phlegm, presence of phlegm despite frequent spitting, phlegm with a wet, bloody taste, or spitting phlegm with blood. Coughing with symptoms of wind-cold invading the lungs are copious amounts of white phlegm with traces of bubbles. Phlegm that is white and thin is mostly the result of hollow-cold. Phlegm that is white and thick, and easily expelled is mostly the result of wetness. Yellow and sticky phlegm is caused by heat. White and sticky phlegm is mostly due to weak yin and dry heat. White, clear phlegm with bubbles is caused by hollowness and cold. Bloody phlegm is mostly caused by heat in the lungs or weak yin. Phlegm with a hot bloody taste or fishy taste is phlegm-heat. Phlegm that has a sweet taste is phlegm-wetness, while phlegm that is salty indicates weak kidneys.