QI, the dynamic force responsible for the activity of life, initiates movement, and is the feeling of movement itself. It is also that which defines or gives things their shape. Lack of Qi is evident when someone cannot keep it together or maintain a shape, becoming dissipated or amorphous. Qi refers to the warmth and pulsatory rhythms which separate life from death. The refined essence of food and air becomes pure or Righteous (Zheng) Qi. Defensive (Wei) Qi helps the body adapt to external influences. Qi refers to the resources which the human organism consumes, transforms, stores and transmits.

MOISTURE refers to the body's liquid components, including digestive secretions, synovial, vitreous and cerebrospinal fluid. Moisture creates a buffer between tissues. Moisture is a fluent substance, as well as the process of generating, distributing and storing fluid.

BLOOD gives solidity to the shape that Qi creates. It encompasses all structural and connective tissue in the body. Blood creates and maintains matter, that which we can touch and taste. It is analogous to a stone, while Qi is the sculptor: the action of the sculptor gives the stone its shape. Blood is a viscous substance, as well as the process of generating, distributing and storing nutrients.

By itself, Blood is passive, inert and thick and tends to stagnates. It is Qi, active and warm, which moves the Blood. By itself, Qi has no material expression and no source for renewal. Blood is the material basis of Qi, linking it with physical form. They are mutually dependent upon each other: where Qi goes, Blood flows and Blood is the mother of Qi.

ESSENCE can be considered the most fundamental constituent in that it is the basis from which all else arises, including the ovum, sperm and genetic material itself. We are endowed at birth with Essence, which is replenished on a daily basis by food and air. Longevity is dictated by the quality and amount of Essence. Like Qi, Moisture and Blood, Essence can be eroded by abuses such as stress, overwork, exhaustion, sexual excess and poor nutrition.

SHEN refers to the organizing force of the self. It is more immaterial (Yang) than Qi, just as Essence is more dense (Yin) than Blood. To comfort the Shen is to soothe the Spirit and relax the Mind. The term Shen-Jing refers to the totality of an individual, encompassing both the tangible and intangible realms of personal experience. Shen is responsible for the integrative function, and is undermined by anxiety and stress.

Qi, Moisture, Blood, Essence and Shen are interdependent, co-generating, and mutually regulating constituents and processes. Moisture cannot be separated from the function of moisturizing, Blood from nourishing, or Qi from moving. Without proper Moisture, Qi becomes Hot and agitated and Blood dries up and stagnates. Without Blood, Moisture is dispersed and Qi is scattered. Without Qi, both Moisture and Blood stagnate. Without Essence, the body has no material source. Without Shen the body lacks presence, having neither Spirit nor Mind.