The relationship between the lung and the kidney is signified by respiration and fluid metabolism. The lung regulates water passage and the kidney controls water. The coordination of the lung and the kidney maintains the normal distribution and excretion of water. Besides, the lung governs respiration and the kidney receives qi. The lung and the kidney work together to accomplish respiratory activity and ensure air exchange between the internal and the external. 

 

 

Pathologically, disorder of the lung in regulating water passage and weakness of the kidney in transforming qi affect each other and cause disturbance in water metabolism, leading to edema and oliguria; failure of the lung to disperse and descend and failure of the kidney to receive qi also affect each other and causes disorder in respiration, bringing on symptoms of cough, chest oppression, shortness of breath and frequent dyspnea, etc.