Traditional Chinese medicine formula Zhenwu Decoction is used to treat spleen and kidney yang deficiency. Zhenwu Decoction disperses cold and dampness, promotes urination, and clears fire while promoting water drainage. Why do traditional Chinese medicine practitioners believe that Zhenwu Decoction is better than Xiaoqinglong Decoction for treating spleen and kidney yang deficiency?
Xiaoqinglong Decoction is used to treat exterior diseases with unresolved water dampness, which are characterized by both internal and external coldness and fullness. Zhenwu Decoction is used to treat exterior diseases with resolved water dampness, which are characterized by both internal and external coldness and deficiency. Zhenwu, the god of water in the north, is the name of the decoction, symbolizing its function in calming water. In the human body, the spleen controls water, while the kidneys are responsible for water metabolism. The kidneys support the spleen and regulate the movement of water. If the kidneys lack yang, even if the spleen functions properly, the gate of the kidneys will not open, causing water to overflow and lead to symptoms of water retention. By using Aconite to warm the kidneys and strengthen the original yang, the water can be regulated. By using Atractylodes to dry dampness and strengthen the middle, the water can be controlled.
Ginger disperses coldness and assists Aconite in replenishing yang, which corresponds to the intention of resolving water in the main water system. Poria cocos seeps dampness and assists Atractylodes in strengthening the earth, which corresponds to the method of controlling water. The essence of Peony's sourness lies in its ability to contain. This is the profound understanding of Zhang Zhongjing, a famous physician in ancient China. The human body's yang is rooted in yin, so if yang is replenished only with pungent and hot herbs without the assistance of sour-containing herbs, the true yang may escape. The use of Peony is to quickly contain yang and return it to its roots in yin.
From this perspective, it can be understood that the reason why mistakenly taking Xiaoqinglong Decoction can lead to sweating and yang deficiency is because Peony, which is necessary in yang-replenishing herbs, is missing. The omission of Peony also leads to diarrhea, as yang cannot be dispersed externally. Adding dried ginger is to warm the middle and overcome coldness. When water and coldness damage the lungs, coughing may occur. Adding Xixin and dried ginger disperses water coldness. Adding Schisandra consolidates lung qi. If there is frequent urination, Poria cocos is removed because even though it is cold, it cannot stop water. If there is vomiting, Aconite is removed and the amount of fresh ginger is doubled because the disease is not in the lower burner but in water stagnation in the stomach. Therefore, it is not necessary to warm the kidneys to promote water drainage, but rather to warm the stomach to disperse water. Additionally, the function of fresh ginger is to stop vomiting.
