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2. Kidneys rule water

The kidney's "water gate" regulates fluid distribution in the body.
The kidneys play an important role in water movement and balance of the whole body. They do this through a kidney yang process called vaporization. Vaporization is the process by which fluids are separated into clean and turbid (unclean) portions. Clean fluid is "vaporized" by the kidneys and sent back to the lungs for redistribution throughout the body while turbid fluid is sent to the bladder by the kidneys for excretion as urine. This type of regulation of body fluids is also called the "opening and closing of the water gate."

Having a balance between kidney yin and yang functions are necessary for normal functioning of the opening and closing of the water gate and the regulation of fluid movement which both control urination. However, when kidney-yin and kidney-yang are unbalanced, the opening and closing of the water gate is abnormal, disturbing normal fluid movement. For example, in the case of a yang-deficiency and yin-excess, there is more closing than opening of the water gate, which leads to problems of urine production and excretion. This gives rise to symptoms of scanty urine and edema (generalized swelling). In the case of a yin-deficiency and yang-excess, there are many more incidences of opening the water gate, and problems like polyuria (excess urine production) will appear. Other organs, like as the lungs, spleen and bladder, are also dependent on the vaporization function of the kidney to regulate fluid movement. Therefore, the kidneys' vaporization control on the opening and closing of the water gate is crucial in balancing the fluid movement throughout the body.

Vaporization Function of the Kidneys