This theory of Qi, Blood, Essence & Fluid in TCM shows physiological functions of the body.

Qi is the Life force that circles around the body and makes everything move. Blood and fluid are similar to orthodox medicine – blood circulates in the blood vessels to deliver nutrients to all parts of the body; Fluid is produced within the body by various organs and it intermingles with the fluids that we drink. The Essence is released within the body which can not be seen but has powerful functions for the whole body’s relative homeostasis. This Essence theory can be interpreted as the endocrine system and the nerve system especially the autonomic nervous system in Orthodox medicine. Therefore, one can see from here that the body’s twelve organ systems are supporting each other and working together to achieve the relative homeostasis of the body for good health and wellbeing.