Cough is said to be without phlegm but with sound, the lung is injured and unclear; cough is without sound but with phlegm, the spleen dampness moves and becomes phlegm; cough is said to be with phlegm but with sound, because the lung is injured and the spleen dampness moves and coughs. Chinese medicine classifies coughs into two types according to their causes: 1. External coughs: they are divided into three types: wind-cold attacking the lungs, wind-heat offending the lungs and wind-dry injury to the lungs. External coughs can be treated by dispelling wind, dispersing cold and moistening dryness to relieve cough symptoms. 2. Internal coughs are divided into four types: phlegm-dampness in the lung, phlegm-heat in the lung, liver-fire in the lung and lung-yin deficiency. The main principle of treating internal injury cough is to dispel wind and stop coughing, which, together with the regulation of the five organs, can significantly relieve the symptoms.