The Gall Bladder is attached to Gan, and excretes bile, taking part in food digestion, and so it is classified as one of the six Fu-viscera. However, it is also classified as an extra ordinary viscus because, like the five Zang-viscera, it stores an essential substance but neither contacts nor digests food directly. Unlike Yang organs, it does not connect directly with the exterior, receive food, or transport nourishment. The Gall Bladder is considered “a Fu-viscera of juice” in TCM. It is an empty sac which stores bile, a purified, bitter-tasting, yellowish fluid. Bile is secreted by Gan and enters the Gall Bladder by means of Gan’s dredging and dispersing action. If Gan fails to dredge and disperse, or if an obstruction impedes bile excretion, digestion and absorption will be disturbed, leading to abdominal distension, anorexia, hypochondriac pain, bitter-tasting vomit, or even jaundice.
The externally–internally related Gall Bladder and Gan are linked by their meridians.
TCM has noted over centuries of clinical observation that the Gall Bladder controls decision-making, and influences one’s courage and initiative. Thus, bravery is related to the Gall Bladder. The Basic Questions says, “The Gall Bladder (with its aura and meridian as one union) is the upright official that takes decisions” . If Gall Bladder-Qi is deficient, a person may be timid and indecisive; if ample, a person will have emotional fortitude and courage, and will not only be able to make appropriate decisions but also to enact them. The capacity to make decisions and choose sound life goals depends largely on the healthy influence of Gan and the Gall Bladder, and is also supported by Xin.
Diagnosis and treatment of some mental and emotional pathology, such as unreasonable fears and anxiety, insomnia, or dream-disturbed sleep, can be assessed and chosen after observing the Gall Bladder’s condition. Treatment may include acupuncture along the Gall Bladder Meridian.
The physiological functions of the gall bladder
(1) The gall bladder relates to Gan
Gan-secreted bile enters the Gall Bladder. As Gan’s failure to optimally dredge and disperse affects bile excretion and disturbs digestion and absorption, so does the Gall Bladder’s failure to efficiently excrete bile adversely affect Gan’s 
dredging and dispersing action. Therefore, Gan and the Gall Bladder may suffer simultaneous illness. Examples are Fire of both Gan and the Gall Bladder, or Damp–Heat in Gan and the Gall Bladder which inhibits bile excretion, causing hypochondriac pain, jaundice, and anorexia.
(2) The gall bladder regulates decision-making
Gan influences-life strategies, planning, and the calming or normalizing of emotions. Thus, the Spirit activities of Gall Bladder viscera are also closely related.