Discussion on the Idea of Differentiation and Treatment of Lung-kidney Qi Deficiency in COPD Stable Period from the Perspective of Water-silver Interaction Theory

The stable phase of chronic obstructive pulmonary disease (COPD) is characterized by lung-kidney qi deficiency as its core pathogenesis, presenting with persistent clinical manifestations that severely impair patients quality of life. This study systematically explores the etiology, pathogenesis, clinical features, and therapeutic strategies of lung-kidney qi deficiency syndrome during COPD stability based on the “metal-water mutual generation” theory in Traditional Chinese Medicine (TCM). Theoretical analysis reveals that impaired lung qi deficiency disrupts downward movement, leading to kidney qi deficiency through maternal dysfunction, which exacerbates dyspnea due to kidneys inability to retain qi, forming a vicious cycle. Clinical management should adhere to the principle of “lung-kidney mutual regulation and metal-water mutual support,” focusing on lung-tonifying qi replenishment and kidney qi retention while incorporating spleen-strengthening phlegm-resolving therapies and blood circulation activation. Common formulas include modified Bu Fei Tang (Lung-Tonifying Decoction) or Qi-Regulating Seven-Ingredient Decoction, combined with external therapies like acupoint patch application and moxibustion. Modern research confirms that this TCM approach of lung-kidney co-treatment based on metal-water theory significantly improves patients pulmonary function, exercise endurance, and immune function, providing an effective management strategy for COPD stability.