The Source

The source of the body fluids: how food and drink are transformed into living moisture

The organic body fluids do not simply appear by themselves. They are continuously produced, transported, transformed and excreted through a complex interaction of organs described in Traditional Chinese Medicine. Understanding the source and circulation of Jin Ye is essential in TCM because it explains why certain organs play such a central role in fluid metabolism and why disorders of fluids are closely connected with the functions of the Spleen, Lung and Kidneys.

Food and drink as the raw material

The organic body fluids originate from the food and drink consumed every day. This makes them a Postnatal substance, continuously replenished through digestion, unlike Prenatal Jing, which is inherited at conception and gradually declines over the course of life. Good nutrition and healthy digestive function are therefore primary requirements for producing sufficient body fluids of good quality.

The Spleen as the starting point: separating pure from impure

The transformation process begins with the Spleen. After the Stomach has received food and "rotted and ripened" it, using the traditional TCM description of digestion, the Spleen separates the useful Essence from waste material. This separation of pure from impure is a fundamental mechanism in TCM physiology: the pure rises and the impure descends.

The Spleen sends the pure portion of the fluids upward to the Lung. The Lung distributes part of these fluids to the skin, contributing to moistening of the body surface and regulation of perspiration, while another portion is sent onward toward the Kidneys.

Further processing: Small Intestine, Bladder and Large Intestine

The impure portion of the fluids descends toward the Small Intestine. A second separation takes place there: the Small Intestine again distinguishes pure from impure. The pure portion is sent to the Bladder, while the impure portion continues to the Large Intestine, where it is further concentrated and ultimately eliminated with the stool.

In TCM, the Bladder is not merely a reservoir for urine but also participates actively in fluid transformation. It performs another separation. The pure portion received by the Bladder is sent upward toward the Lungs to moisten them, while the impure portion leaves the body as urine. Through these repeated stages of separation, the body extracts as much useful fluid as possible while efficiently eliminating waste fluids.

The direction of movement: upward and downward

A crucial principle of fluid physiology is direction. Pure fluids must be transported upward toward the Lung, skin, head and sensory organs. Impure fluids must descend toward the Large Intestine and Bladder and ultimately leave the body. Correct ascent and descent depend on the smooth movement of Qi, because Qi provides the movement and direction of the fluids.

When Qi becomes weak or stagnant, fluid circulation may lose its proper direction. Pure fluids that fail to rise may contribute to dryness of the head and sensory organs. Impure fluids that fail to descend may accumulate and contribute to swelling, retention and Phlegm. Treatment therefore often includes restoring the proper movement and direction of Qi.

The three key organs: Lung, Spleen and Kidneys

Although many organs contribute to the transformation, transportation and excretion of body fluids, the Lung, Spleen and Kidneys are the principal organs. The Spleen is the primary producer and separator. The Lung acts as the distributor, spreading fluids toward the body surface and participating in the regulation of perspiration. The Kidneys provide the deepest level of regulation, receiving and transforming fluids and supplying the Yang warmth that supports fluid transformation throughout the body.

A weak Spleen may result in insufficient transformation and the formation of Phlegm. Weak Lung function may contribute to dryness of the skin and inadequate distribution of fluids. Weak Kidney function may contribute to oedema, frequent urination or, conversely, fluid retention. Understanding the origin and circulation of Jin Ye therefore provides a precise framework for interpreting and treating fluid pathology in TCM.