Linggui Zhugan Decoction for Phlegm-Fluid Cough and Pleural Effusion

Linggui Zhugan Tang (Poria, Cinnamon Twig, Atractylodes, and Licorice Decoction) is the principal formula in the Shanghan Lun for treating phlegm-fluid (tan yin) disorders. The original text of the Shanghan Lun reads: "In cold damage, after vomiting or purgation, there is inverted fullness below the heart, qi surging upward to the chest, dizziness upon rising, and a deep, tight pulse; if sweating is promoted, the channels are moved and the body trembles and shakes—Linggui Zhugan Tang governs."

Composition and preparation: Fuling (Poria) 4 liang, Guizhi (Cinnamomi Ramus) 3 liang, Baizhu (Atractylodis Macrocephalae Rhizoma) and Gancao (Glycyrrhizae Radix, processed) each 2 liang. Boil these four herbs in six sheng of water to three sheng, strain, and take warm in three divided doses.

Modern conversions commonly give Fuling 12g, Guizhi 9g, Baizhu 6g, processed Gancao 6g. But when treating major conditions such as pleural effusion, I use larger doses, generally converting one Han liang to 15g: Fuling 60g, Guizhi 45g, Baizhu 30g, processed Gancao 30g. It is best to add some lung-qi-moving herbs such as Tinglizi (Descurainiae Semen), Pipaye (Eriobotryae Folium), Xingren (Armeniacae Semen), and diuretic herbs such as Niuxi (Cyathulae Radix) and Cheqianzi (Plantaginis Semen). Decoct twice, divide into three equal portions, and take one portion after each meal (morning, noon, evening).

This formula uses Fuling, which fortifies the spleen and percolates fluid, as the sovereign, together with Baizhu to fortify the spleen and boost qi, thereby cutting off the source of phlegm-fluid. Guizhi both warms and transforms yang qi and percolates fluid (in Wuling San, too, Guizhi warms yang and promotes diuresis). Processed Gancao both harmonizes the other herbs and controls the warm-drying nature of Guizhi. Thus, although the formula contains only four herbs, TCM physicians of every era have esteemed it as the principal formula for phlegm-fluid disorders.

The main symptom of phlegm-fluid is "inverted fullness below the heart," which chiefly means chest and abdominal oppression and discomfort; "qi surging upward to the chest" means the patient feels a counterflow of qi rising from below to strike the chest. Patients with phlegm-fluid disorders also experience dizziness and trembling, unsteadiness of the body; the pulse is often deep and tight, or wiry. These symptoms broadly correspond to what modern medicine calls chest tightness, shortness of breath, and tremor.

Phlegm-fluid patients have these symptoms because the respiratory tract or upper digestive tract contains a large amount of phlegm or retained fluid. For retained fluid, TCM generally follows the principle: if above, promote sweating; if below, promote urination. But this fluid in the middle jiao lies neither above nor below; sweating cannot solve it, and simple diuresis cannot solve it either. Hence Linggui Zhugan Tang uses the combined approach of fortifying the spleen, warming yang, and percolating fluid.

This formula can be used in treating coronary heart disease, asthma, rhinitis, neurosis, emphysema, refractory cough and wheezing, pyloric obstruction, excessive leukorrhea in women, rheumatoid arthritis, rheumatic heart disease, pleural effusion, and gastric retention, among many other conditions.

Whenever the clinical picture includes chest tightness, shortness of breath, tremor, and a deep-tight or wiry pulse, it generally belongs to the TCM phlegm-fluid disorder, and Linggui Zhugan Tang may be prescribed.