As a Firm-Characterized Organ.
"Firm-characterized" refers to its staunchness and restlessness. The liver was likened to the "general" by the ancient doctors, who took its general disposition to be firm, sharp, and movement-oriented. For this reason, when the liver is diseased, liver-qi tends toward movability and hyperactivity. This is why there is a saying that the liver is characterized by "its body pertaining to yin with its function to yang. " "The body pertaining to yin" implies that the liver is an organ storing blood and located in the lower, both pertaining to yin. The normal functioning of the liver relies upon the nourishment of liver-blood. Being a firm-characterized organ, it can not function well without moistness and nourishment. "The function pertaining to yang" refers to two aspects, first, from the physiological perspective, ministerial fire resides in the liver, which is an organ of wind-wood, which dominates ascending and moving, pertaining to yang; and secondly, from the pathological perspective, liver-yin and liver-blood are prone to be in deficiency, while liver-yang tends toward hyperactivity.

When the liver is diseased, ascendant hyperactivity of liver-yang often appears, causing liver-wind stirring within, and resulting in such symptoms as dizziness and vertigo, spasm of the tendons, convulsion, and so on. In addition, failure of the liver in its conducting and dispersing functions may cause qi stagnation and blood stasis. Depressed liver-qi may turn into the fire and consume liver-yin and liver-blood, leading further to ascendant hyperactivity of liver-yang. Generally, during pathological processes, the liver is unique in that the morbidity of its yang-qi is usually attributable to superabundance, while yang-qi of other viscera is prone to deficiency. Similarly, liver-yin and liver-blood are usually prone to deficiency. This is summed up in the axiom, "Liver-qi and liver-yang are usually abundant, while liver-yin and liver-blood are usually insufficient. "