TCM Theory - Zang Fu organs

There are two categories of organs in TCM. The Zang, or Yin organs are the solid organs, and the Fu, or Yang organs, are the hollow organs. Each Zang organ has a corresponding Fu organ. All of the organs are interrelated in a complex network as described by the Five Element Theory. (See ‘The theory of the five elements (Wu Xing)’ below)

The organs in traditional Chinese medicine do not literally correspond to the anatomical organs of Western medical science, such as the heart, liver or spleen. Instead, they are better understood in terms of the functions they perform, which incorporate energetic, emotional and spiritual aspects as well as physical. The meaning of the Chinese organs is generally broader than that of the organs as understood by Western medicine.

The Zang, or Yin Organs in Traditional Chinese Medicine

The Zang, or Yin organs are the ‘solid’ organs, considered to be more vital. Their function is to produce, transform, regulate and store.

• Liver: Considered to be the General of the body, the liver stores the blood and directs the flow of blood and Qi (vital energy). Regulation of the flow of Qi affects mood, digestion, bile flow and menstruation. When the smooth flow of Qi is obstructed, it can lead to emotional issues including anger and depression.
• Heart: Often called the ‘Emperor of the body’, the heart rules over blood circulation and vessels, and controls sweating. Shen, the mind or spirit, resides in the Heart, and is responsible for mental processes, thinking, memory, sleep and dreams. Physically, the Heart of TCM encompasses the heart, circulatory system and brain of Western medicine
• Spleen: The Spleen regulates metabolism and assimilates food, transforming it into blood and Qi. In addition, the Spleen is in charge of keeping the blood in the vessels.
• Lungs: Taking in pure air and exhaling turbid air, the Lungs control respiration and produce and govern Qi. They are closely related to the Heart and aid in the circulation of the blood. Since the Lungs are exposed to the exterior, they are particularly vulnerable to external pathogens.
• Kidneys: The Kidneys are in charge of fluid metabolism and the reproductive organs, and also rule the marrow, bones and teeth. They store Jing, or Essence, an inherited substance that determines the constitutional strength of each individual at birth. The Kidneys provide the foundation of Yin and Yang for the body as a whole.

The Fu, or Yang Organs in Traditional Chinese Medicine

The Fu, or Yang organs are the ‘hollow’ organs whose function is to hold, transport, break down and absorb.

• Gall Bladder: Paired with the Liver, and a Fu organ that is not directly involved with processing food or drink, the Gall Bladder stores and releases bile, a pure fluid. The Gall Bladder is in charge of making decisions by giving courage and initiative to take action.
• Small Intestine: Paired with the Heart, the primary function of the Small Intestine is to receive food from the Stomach and "separate the pure from the impure," sending the useful nutrients to the Spleen and passing the solid and liquid waste to the Large Intestine and Urinary Bladder to be eliminated. The Small Intestine psychologically helps to distinguish between what is right and true and what is not.
• Stomach: As the partner of the Spleen, the Stomach receives food and is in charge of digestion, a process known in TCM as "ripening" or "rotting." The Stomach has a descending action, and conditions such as belching, hiccupping or nausea indicate that Stomach Qi is not descending properly.
• Large Intestine: The partner of the Lungs, the main role of the Large Intestine is to reabsorb water and eliminate waste. This is analogous to the Lungs' function of extracting what is beneficial from the air and expelling what is harmful. The Large Intestine is associated with the ability to let go of that which is unnecessary, both in a physical and emotional sense.
• Urinary Bladder: Paired with the Kidneys, the Urinary Bladder helps to regulate fluid metabolism by receiving, storing and excreting urine.

As the organs of TCM theory generally describe the processes outlined above, rather than the physical parts of the human body, TCM diagnosis involving these organs does not necessarily denote an issue with the physical organ itself. For example, ‘Liver Qi stagnation’ does not necessarily mean that there is something wrong with the livers of the human body; nor does ‘Kidney Yang deficiency’ necessarily suggest dysfunction or an issue with the physical kidneys.