The Water is composed of the Kidneys (Yin) and the Bladder (Yang).

According to the generating sequence:

• Water is the mother of Wood. The Kidneys are the mother of the Liver. Kidney-Yin nourishes Liver-Blood, also, the Kidneys control the bones and the Liver controls the sinews, both have a relationship that cannot be separated. See: Liver- and Kidney-Yin deficiency.

According to the controlling sequence:

• Water is the grandmother of Fire. The Kidneys control the Heart. The relationship between Heart and Kidneys represents a vital balance, it represents the basic balance of body Yin and Yang. The Kidneys govern the water that must flow upward and nourish the Heart. The Heart governs the fire that must descend and warm the Kidneys. This relationship is of mutual assistance and nourishment. See: Rupture of Heart and Kidneys.