Qi controls and restrains liquids such as Blood, Body Fluid, and sperm to prevent undue loss. Spleen-Qi holds the Blood within the vessels, Kidney-Qi and Bladder-Qi hold urine, Lung-Qi holds sweat, and Kidney-Qi holds sperm. For example, healthy Qi can contain Blood within the vessels and prevents its flow out of the vessels, but if Qi is weakened, it can result in loss of Blood and Body Fluid. This is also seen as sweating, urinary incontinence, spermatorrhea or nocturnal emissions, and even miscarriage.
It is important to note that fixating and propelling are opposite yet complementary Qi functions. With their mutual coordination, Qi maintains normal blood circulation and water metabolism.
Qi transformation is the base of life activities. This means that Qi movement produces changes, and the metabolism of food to Essence, Qi, Blood, Body Fluid, and the inter-transformation of those substances. Qi is the motive force of all physiological processes and functions of the viscera and organs. It can assume many different forms and functions. The changes caused by the circulation of Qi are transforming, changing, transporting, entering, exiting, ascending, descending, mixing, impacting, etc. All these Qi functions, the most basic activities of life, are generally called “transformation of Qi” (Qihua, ). Qihua is the sum of all the active movements, of life, no matter how discrete. This concept is more complicated than the CWM understanding, except in the case of some physical and chemical mechanisms which are now viewed as relating to subtle life activities. The two most important movements of Qi transformation relate to Heaven and Earth. Heaven pertains to Yang, and descends; Earth pertains to Yin, and ascends.
The Basic Questions says, “Descending pertains to Heaven; ascending pertains to Earth. The Qi of Heaven flows down to Earth; the Qi of Earth rises like steam to Heaven. Both attract and are the reason for each other; this enables constant change and transformation” .
Life activities of Qi can be simplified as follows: the body absorbs nutrients from the external world and transforms them into Essence, Qi, Blood, and Body Fluid; then, in cooperation with the cells opening and closing, Essence, Qi, Blood, and Body Fluid transform and metabolize into each other and circulate to nourish every part of the body. Nourishment can be considered part of Blood circulation. But TCM says, “Qi is the commander of Blood; Blood is the mother of Qi.” All waste substances are excreted from the body. If Qi transformation is disordered, it can lead to disease and even death.