The Liver (Chinese: 肝; pinyin: gān) is one of the zàng organs stipulated by traditional Chinese medicine (TCM). It is a functionally defined entity and not equivalent to the anatomical organ of the same name.

In the context of the zang-fu concept

As a zàng organ, the Liver is considered to be yin in nature. Its associated yang fu organ is the Gallbladder. Both the Liver and Gallbladder are attributed to the Wood element and the season of spring in traditional Chinese Wuxing theory.

Regarding its stipulated functions, the Liver

• governs "unclogging and deflation" (Chinese: 疏泄; pinyin: shū-xiè)^[1] primarily of qì and emotions. The free flow and harmony of qì in turn will ensure the harmonious interaction and flow of blood, digestion, and Jinye.
  • the free flow of qì and xuě (blood) is particularly significant since TCM stipulates that stagnation of that flow will cause pain.
  • by association via its respective element each zàng and Fu organ is the origin of a certain emotion reflected in the Shen or overall spirit of the patient. The free flow of these five (and other) emotions is thus linked to the unrestrained and harmonious circulation of the qì of the zàng organs.
• "stores" (藏, pinyin: cáng)^[2] blood
• opens into the eyes^[3]
• governs the tendons
• reflects in the nails
• Associated with the emotion of anger (怒, pinyin: nǜ)^[4]
• houses the hún (魂, "Ethereal Soul")

Its associated body fluid is tearing.
The Liver function is regarded to be strongest between 1–3 am. Its blood is responsible for the repetitive cycles of human life, for example menstruation. The Huang Di Nei Jing describes the Liver as "the general of an army". It secretes bile, which is stored in the Gallbladder. A properly functioning Liver organ will ensure that the tendons are properly nourished and not too tense or gristly. The normal direction of Liver qi is outwards. When it "rebels" it can attack the Spleen, causing nausea and poor appetite. Dysfunction of the Liver typically presents as irritability, anger, poor self esteem,headaches, dysmenorrhea, belches, a sour taste in the mouth, distension, pain under the costal arches, pain in the upper abdomen, tremors/numbness/stiffness of the limbs, blurry vision, or jaundice.^[5] Liver blood stagnation may lead to amenorrhea, blood clotting, or a bearing down sensation with menstruation.