Kidney governs water

The kidney distills fluids, regulates their distribution, and discharges waste water, thereby maintaining normal water metabolism in the body. For this reason, the kidney is said to govern water. Body fluids are derived from fluids taken in by the stomach. Through the spleen’s movement and transformation and the lung’s regulation of the waterways, they are distributed throughout the body, and waste water is carried down to the bladder before being discharged. The qì transformation of the kidney plays a vital role in this. This is why it is said that the kidney governs water.

Impairment of this action due to kidney yáng vacuity can either cause disorders of fluid metabolism such as scant urine or water swelling or water containment failure, characterized by long voidings of clear urine or profuse urination at night. The function of the bladder is to store and discharge urine and is closely related to the kidney. Storage relies on the retentive power of kidney qì, while discharge relies on the power of the kidney to permit flow. This is known as the opening and closing function of the kidney that controls the flow of urine down to the bladder, and enables the bladder to store up to a certain amount of urine before permitting its discharge. Plain Questions (素问 sù wèn, líng lán mì diǎn lùn) says, The bladder... stores fluid, and by qì transformation discharges it. In reality, qì transformation referred to here is a function of the kidney. According to Plain Questions (素问 sù wèn, xuān míng wǔ qì piān), Inhibition of the bladder manifests as dribbling urinary block, and its failure to ensure containment, as enuresis.

Pathologies associated with the bladder include dribbling urinary block, dribble after voiding, frequent urination, urinary urgency, painful urination, enuresis, or urinary incontinence, which in the absence of disease of the bladder itself are generally attributed to disease of the kidney.