Extraordinary Fu Organs

Extraordinary Fu Organs

Aside from the regular Yin (Zang) and Yang (Fu) organs, there are also six Extraordinary Fu Organs, which complete the theory of Chinese physiology. They are given this name because they function like a Yin organ in that they store Yin essence, but have the shape of a Yang organ, they are hollow.

The Extraordinary Fu organs are:

  • The Uterus
  • The Brain
  • Marrow
  • The Bones
  • The Blood Vessels
  • The Gall Bladder.

Each of the six Extraordinary Fu Organs store some form of Yin essence, either from the Kidneys, Marrow or Blood. Functionally they are all directly or indirectly related to the Kidneys.

The Uterus

It is the most important of them all. It has the function of regulating menstruation, conception and pregnancy. It is closely related to the Kidneys, and the Ren Mai and Chong Mai meridians. The state of health of the Uterus is ultimately linked to the physiological balance of the Kidneys. If Kidney Qi or Essence is weak, or if Blood is deficient, the Ren and Chong meridians will be empty, thus the supply of Qi and Blood to the Uterus will be deficient, resulting in disharmony and disease.

The intimate connection between the Uterus and Blood also extends to the Heart, Spleen and Liver, thus any pathological condition affecting these organs can have an adverse effect on the Uterus itself. This can lead to irregular or painful periods, scanty periods, infertility or habitual miscarriage.

The Brain

The Brain is responsible for controlling and regulating both life and mental activities. TCM theory states that Kidney-Essence produces the Marrow which moves to fill the spinal cord and Brain as such, it is also known as the “Sea of Marrow” in Chinese medicine. This makes it functionally related to the Kidneys. The Brain is also dependent on the Heart, in particular, Heart-Blood for nourishment.

Accordingly, if Kidney-Essence and Heart-Blood are abundant, good health results, manifesting as good vitality, clear thinking, fluent speech and strong memory. On the other hand, if there is deficiency, it will lead to poor memory, confused thinking, dizziness, lack of concentration, blurred vision or in more severe cases, mental disorder.


This is the common matrix of Bone-marrow and the Brain which fills the spinal cord and the Brain. Like the other Extraordinary Fu organs, there is a string connection to the Kidneys, as the Marrow is produced by Kidney-Essence. The function of Marrow in Chinese medicine should also not be confused with that of Western biomedicine. In TCM the Marrow is responsible for nourishing the Barin and spinal cord, and for forming the Bone-marrow.

The Bones

They are hollow, yet store the Marrow so are classified as extraordinary. The Bones are nourished by Kidney-Essence and Marrow, which, if deficient, result in weakening of the bone, causing problems with standing and walking.

Clinically, it is possible to exploit the relationship between the Bone and the Kidneys, by treating the Kidneys to speed up the healing of bone fractures.

The Blood Vessels

Much like the Bones, Blood vessels are considered an Extraordinary Fu organ because they are hollow, yet contain the Blood, a Yin essence. They are indirectly related to the Kidneys, as Kidney-Essence produces Marrow, which is involved in Blood production. Additonally, the Yuan Qi contributes to the trasnformation of Gu Qi into Blood.

The Gall Bladder

This organ is unqiue in Zang-Fu theory in that it belongs simultaneously to the six Fu organs and the six Extraordinary Fu organs. This is due it being hollow, yet storing Bile, a “pure” substance not related to food or drink. Other than this point, there is no clinical significance in the Gall Bladder being placed with the other Extraordinary organs as its functions do not differ from those under its classifcation as a Fu organ.