Cough

Sudden expulsion of air from the lung with an explosive noise, usually in a series of efforts. The Chinese term is composed of two characters, 咳 ké and 嗽 sòu. In The Inner Classic (内经 nèi jīng), these two characters have the same meaning, and this usage prevailed until the Sòng Dynasty (CE 960–1279), when Liú Wán-Sù (刘完素, aka Hé-Jiān 河间, c. CE 1120–1200) introduced a distinction: Ké [sonorous cough] means a cough that produces sound but no matter, and arises when lung qì is damaged and loses its clarity; sòu [productive cough] is a cough that produces matter without sound and is attributed to spleen dampness stirring to form phlegm; ké sòu [sonorous and productive cough], is one with phlegm and sound, and arises when damage to lung qì stirs dampness in the spleen so that the ké becomes sòu.

From that time on, some followed The Inner Classic (内经 nèi jīng) in treating the characters as synonymous, whereas others adopted the distinction made by Liú Wán-Su5. In modern literature, the distinct forms are often referred to as gān ké, dry cough, and tán ké, phlegm cough, and both are referred to together by the combined form ké sòu. Cough can be caused by external evils invading the lung or by internal damage to organs affecting the lung; hence the notion that Cough does not stop at the lung; but never leaves the lung. In other words the pathomechanisms of cough are not limited to the lung but always involve it. Cough may be attributable to an exuberant evil (external evils or phlegm-damp) or to vacuity. External contraction cough may be caused by wind-cold, wind-heat, or dryness. The cough itself can in some cases indicate the cause. For example, a cough that is pronounced in the daytime is usually attributed to heat or dryness; one that gets worse at night is more likely to be attributable to spleen-kidney debilitation or to exuberant phlegm-damp. However, correlation with other signs is necessary for accurate diagnosis. The main patterns can be diagnosed as follows.

Patterns

Wind-cold (风寒 fēng hán) fettering the lung causes a heavy turbid sounding cough with expectoration of thin white phlegm and accompanied by runny nose with clear snivel, heat effusion and aversion to cold, body pains, absence of sweating and a floating pulse.

Wind-heat (风热 fēng rè) invading the lung gives raise to an ungratifying coughing sound, expectoration of thick yellow phlegm, dry mouth and sore throat, aversion to cold with heat effusion.

Dryness evil (燥邪 zào xié) damaging the lung is characterized by no phlegm and a clear crisp voice, or phlegm that is difficult to expectorate, a dry mouth and throat, dry skin, hoarse voice, and pain in the chest when coughing.

Phlegm-damp (痰湿 tán shī) obstructing the lung is characterized by a cough that ceases after expectoration, and thick sticky phlegm that is easy to expectorate and is accompanied by distension and oppression in the stomach duct and abdomen, nausea and torpid intake, sloppy stool, slimy tongue fur, and slippery pulse. It arises when a vacuous spleen failing to move water-damp allows the gradual collection of phlegm that obstructs the lung.

Liver fire (肝火 gān huǒ) invading the lung causes cough and counterflow qì, phlegm like rotted threads that is difficult to expectorate, pain in the rib-side when coughing, dry pharynx and mouth, impatience, agitation, and irascibility, oppression in the chest, sighing, generalized heat and red face, and a rapid stringlike pulse.

Lung-spleen qì vacuity (肺脾气虚 fèi pí qì xū) cough is characterized by copious thin white phlegm, low voice, shortness of breath, reduced eating, sloppy stool, bright-white facial complexion, spontaneous sweating and fear of wind, and a forceless vacuous pulse.

Kidney yáng vacuity (肾阳虚 shèn yáng xū) cough is usually associated with hasty panting and labored breathing, clear thin foamy phlegm, vacuity swelling of the face, soft enlarged tongue, and, in severe cases, enuresis accompanying coughing.

Lung-kidney yīn vacuity (肺肾阴虚 fèi shèn yīn xū) is an enduring cough with scant sticky phlegm in some cases flecked with blood, accompanied by emaciation, tidal heat, vexation and agitation, reddening of the cheeks, night sweating, dry mouth and pharynx, hoarse voice, red tongue with scant fur, and rapid fine pulse. Cough is often classified and labeled according to cause or nature or time, and less commonly nowadays according to bowel or visceral involvement. See entries listed below.