Vital Substances in Traditional Chinese Medicine: Essence, Qi, Blood, Body Fluids, and Mind

ESSENCE (JING)

Definition and Overview
- Essence is one of the Vital Substances of the body, fundamental to growth, development, and constitutional strength.
- It is categorized into three distinct but interrelated types: Pre-heaven Essence, Post-heaven Essence, and Kidney Essence.
Pre-heaven (Prenatal) Essence
- Source: It is inherited from one’s parents at the moment of conception.
- Function: It is the primary factor that makes each individual unique and determines each person’s basic constitutional make-up, strength, and vitality.
- Relationship with Fire of Gate of Life (Ming Men): Pre-heaven Essence is closely related to the Fire of the Gate of Life, which constitutes the Yang aspect of Essence. Situated between the Kidneys, the Fire of the Gate of Life is the physiological Fire of the body, providing essential warmth for all physiological processes and internal organs. This Fire is present from birth and conception.
- Quantity and Quality: The quantity of Pre-heaven Essence is fixed. However, its quality can be positively influenced through a balanced lifestyle, proper breathing, and practices such as Qi Gong or Tai Ji Quan.
Post-heaven (Postnatal) Essence
- Definition: This is a general term indicating the Essence produced after birth.
- Source: It is refined and extracted from food and fluids by the functions of the Stomach and Spleen.
Kidney Essence
- Composition: Formed by the combination of Pre-heaven Essence and Post-heaven Essence ( $\text{Pre-heaven} + \text{Post-heaven} = \text{Kidney Essence}$ ).
- Function: It plays an extremely important role in human physiology and is more specific than general Essence.
- Maturity: Pre-heaven Essence "matures" into Kidney Essence at puberty. At this stage, it generates "Dew of Heaven" (menstrual blood and ova in women; sperm in men).
- Storage and Circulation: It is stored between the Kidneys and circulates particularly in the Eight Extra Channels ( $\text{Ren}$ , $\text{Chong}$ , $\text{Du}$ , etc.).
The Cycles of Growth, Reproduction, and Development
- Life cycles are traditionally measured in periods of $7$ years for females and $8$ years for males:
- Female Cycles ( $7$ Years):
  - Age $7$ : Kidney energy is abundant; baby teeth are replaced and hair grows.
  - Age $14$ : "Dew of Heaven" arrives; the Ren and Chong channels develop, menstruation begins regularly, and she can conceive.
  - Age $21$ : Essence peaks; wisdom teeth emerge and growth is at its utmost.
  - Age $28$ : Tendons and bones become strong; hair is longest and most flourishing.
  - Age $35$ : Yangming (Stomach/Large Intestine) begins to weaken; the complexion withers and hair begins to fall.
  - Age $42$ : The three Yang channels (Taiyang, Yangming, Shaoyang) are weak; the face darkens and hair turns grey.
  - Age $49$ : Du and Chong channels are empty; "Dew of Heaven" dries up; the uterus is no longer open (menopause).
- Male Cycles ( $8$ Years):
  - Age $8$ : Kidney energy is abundant; hair and teeth grow.
  - Age $16$ : "Dew of Heaven" arrives; Yin and Yang are harmonized, and he can produce children.
  - Age $24$ : Essence peaks; wisdom teeth emerge and growth is at its peak.
  - Age $32$ : Tendons and bones are strong; muscles are full and strong.
  - Age $40$ : Kidney weakens; hair and teeth begin to fall.
  - Age $48$ : Yang Qi is exhausted; the face darkens and hair turns grey.
  - Age $56$ : Liver Qi weakens; tendons cannot move; "Dew of Heaven" is dried up.
  - Age $64$ : Hair and teeth are gone.
Primary Functions of Kidney Essence
- Basis of Kidney Qi: Kidney Essence is fluid-like and belongs to Yin. It serves as the material basis for Kidney Yin to produce Kidney Qi via the heating action (transformation) of Kidney Yang.
- Producer of Marrow: Essence produces Marrow. Marrow, in turn, produces bone marrow and fills the spinal cord and the brain. The brain is referred to as the "Sea of Marrow."
- Basis of Constitutional Strength: It determines resistance to exterior pathogenic factors. While Defensive Qi ( $\text{Wei Qi}$ ) is the primary protector, it draws its strength and root from Kidney Essence.

QI

Types and Origins of Qi
- Original Qi (Yuan Qi):
  - The "Qi form" of Essence, originating between the Kidneys.
  - Constantly replenished by Post-heaven Essence and related to the Ming Men.
  - Relies on the Triple Burner ( $\text{San Jiao}$ ) for circulation through the body.
  - Functions: Motive force for all activities; basis of Kidney Qi; facilitates transformation of Qi and Blood; conduit for the Triple Burner; emerges at Source points ( $\text{Yuan}$ points).
- Food Qi (Gu Qi):
  - Originated from the Stomach and Spleen.
  - It is the origin and basis for the production of both Qi and Blood.
- Gathering Qi (Zong Qi):
  - Nourishes the Heart and Lungs.
  - Promotes Lung functions (controlling Qi and respiration) and Heart functions (governing Blood and vessels).
  - Controls speech and voice strength; promotes blood circulation to extremities.
  - Coordinates with Original Qi to regulate breathing and aid the Kidneys.
- True Qi (Zhen Qi):
  - Originates from Gathering Qi ( $\text{Zong Qi}$ ) and the Lungs.
  - It is the final stage in Qi transformation and assumes two forms: Nutritive Qi and Defensive Qi.
- Nutritive Qi (Ying Qi):
  - Nourishes internal organs.
  - Closely linked to Blood; flows within channels and blood vessels.
  - The specific Qi activated during acupuncture needle insertion.
- Defensive Qi (Wei Qi):
  - Rooted: In the Lower Burner.
  - Nourished: By the Middle Burner.
  - Spread: In the Upper Burner.
  - Characteristics: A coarse form of Qi that circulates outside the channels (between skin and muscle).
  - Functions: Protects against external pathogenic factors; warms muscles; regulates pores by mixing with sweat.
  - Circulation: It circulates $50$ times within a $24$ -hour period: $25$ times during the day and $25$ times at night.
- Central Qi (Zhong Qi): The True Qi of the Stomach and Spleen; refers to Spleen functions of transportation, transformation ( $\text{Yun Hua}$ ), and raising Qi.
- Upright Qi (Zheng Qi): A general term for all Qi types (Defensive, Nutritive, Kidney Essence) that defend the body against "Pathogenic Factors" ( $\text{Xie Qi}$ ).
Functions of Qi
- Transforming: Converting food and fluids into clear (Yang) and turbid (Yin) parts.
- Transporting: Moving vital substances throughout the body (in/out, up/down).
- Holding: Keeping fluids and Qi in their proper places (e.g., holding blood in vessels).
- Raising: Ensuring body structures (organs) are held in place.
- Protecting: Defending from external pathogens (primarily Wei Qi).
- Warming: A function of Yang Qi; all physiological processes depend on warmth.
Directions of Qi Movement
- Lungs: Descends towards the Kidneys; diffuses Defensive Qi and sweat.
- Liver: Ascends; controls the smooth flow of Qi in all directions.
- Kidney: Clear part ascends to Lungs; turbid part descends (e.g., urination).
- Spleen: Ascends towards the Heart and Lungs.
- Stomach: Descends (impure Qi).
- Heart: Heart-Fire descends to meet Kidney-Water.
Pathology of Qi
- Qi Deficiency: Often due to overwork or irregular diet; Lungs, Spleen, Stomach, and Kidneys are most prone.
- Qi Sinking: A consequence of deficiency, leading to organ prolapse.
- Qi Stagnation: Failure of movement, most common in the Liver.
- Qi Rebellious: Qi flowing in the wrong direction (e.g., Stomach Qi ascending instead of descending).

BLOOD (XUE)

Source of Blood
- Originates from Food-Qi ( $\text{Gu Qi}$ ) produced by the Spleen.
- The Lungs and Heart are involved in the transformation process.
- Kidney Essence and Original Qi provide the fundamental basis for its generation.
Functions of Blood
- Nourishing: Main function. Blood is a dense form of Qi that flows with Qi to nourish the whole body.
- Moistening: Prevents tissues (eyes, skin, sinews, hair) from drying out.
- Circulating: Nutritive Qi ( $\text{Ying Qi}$ ) transports and holds Blood.
- Housing the Mind: Blood is the material foundation for the Mind ( $\text{Shen}$ ). As a Yin substance (dense/fluid), it anchors the Mind.
- Menstruation: Blood determines the menstrual cycle; the Liver is the most important organ here.
Organ Relationships to Blood
- Heart: Governs the Blood.
- Spleen: Makes the Blood and holds it in the vessels.
- Liver: Stores the Blood; nourishes sinews, eyes, and uterus.
- Lungs: Sends Food-Qi to the Heart.
- Kidneys: Source of Original Qi and Essence needed for Blood production.
Qi and Blood Relationship
- Qi generates Blood: Food-Qi and Lung-Qi are essential for production.
- Qi moves Blood: Qi is the motive force; without it, Blood is inert.
- Qi holds Blood: Prevents hemorrhages (primarily a Spleen function).
- Blood nourishes Qi: Qi relies on the nutritive function of Blood for its own existence.
Comparison: Qi vs. Blood
- Qi: Yang, active, initiates changes, flexible, activates, quickens, tense/hard, "doing," "becoming," moves forward in time, potential, creative/foster, visionary.
- Blood: Yin, passive, accepts, dense/fluid, relaxes, softens, soft/relax, "non-doing," "being," repetitive cycle, actualization, achieved/recognized, memory.
Pathology of Blood
- Blood Deficiency: Caused by inadequate manufacture (Spleen/Stomach-Qi deficiency). Manifests as scanty periods or amenorrhea (Kidney/Liver deficiency).
- Blood Heat: Often due to Liver-Heat or Liver-Fire. Causes heavy periods and skin diseases.
- Blood Stasis: Failure to move, caused by Qi stagnation, Heat, or Cold. Often results in pain.

BODY FLUIDS (JIN-YE)

Source and Transformation Path
- Fluids enter the Stomach (Source) and are transformed by the Spleen.
- The Small Intestine separates fluids into "Pure" and "Impure."
- Upper Burner (Mist): Lungs diffuse pure parts to the skin and descend fluids to the Kidneys.
- Middle Burner (Maceration Chamber): Spleen/Stomach processing.
- Lower Burner (Drainage Ditch): Bladder and Large Intestine handle excretion/storing.
Types: Jin vs. Ye
- Jin (Fluids): Clear, light, thin, watery. Circulate with Defensive Qi on the exterior (skin/muscles). Move quickly. Controlled by Lungs. Function: Moisten skin/muscles, found in sweat, tears, saliva.
- Ye (Liquids): Turbid, heavy, dense. Circulate with Nutritive Qi in the interior. Move slowly. Controlled by Spleen and Kidneys. Function: Moisten joints, spine, brain, marrow, and sense organ orifices.
Internal Organ Functions in Body Fluids
- Lungs: Regulate the "Water Passage"; control diffusion (skin) and descending (Kidney/Bladder).
- Spleen: Most important organ for transformation, separation, and directional movement of fluids.
- Kidneys: Vaporize fluids to moisten Lungs; Kidney Yang controls many stages of transformation.
- Small Intestine: Separates clear from turbid, controlled by Kidney Yang.
- Bladder: Excretes urine via Qi transformation.
- Triple Burner ( $\text{San Jiao}$ ): Assists in transformation, transportation, and excretion at all stages.
Relationships and Pathology
- Qi and Body Fluids: Qi transforms, transports, and holds fluids. Deficiency leads to leakage (sweat, incontinence). Conversely, fluids nourish Qi; heavy fluid loss leads to Qi deficiency (cold limbs, pallor).
- Blood and Body Fluids: Interchangeable Yin substances. Blood supplements fluids; fluids thin Blood to prevent stagnation.
- Pathology: Deficiency (dryness) or Accumulation (edema, dampness, phlegm).

THE MIND (SHEN)

Nature and The Three Treasures
- The Mind is the most subtle, non-material type of Qi.
- Integration of Essence, Qi, and Mind is called the "Three Treasures."
- The Mind relies on Essence and Qi as its fundamental basis; conversely, emotional stress (disturbed Mind) affects Qi and Essence.
The Five Mental-Spiritual Aspects (The Five Zhi)
- Ethereal Soul ( $\text{Hun}$ ): Pertaining to the Liver.
- Corporeal Soul ( $\text{Po}$ ): Pertaining to the Lungs.
- Intellect ( $\text{Yi}$ ): Pertaining to the Spleen.
- Will-power ( $\text{Zhi}$ ): Pertaining to the Kidneys.
- Mind ( $\text{Shen}$ ): Pertaining to the Heart.
Functions of the Mind
- Consciousness: Totality of thoughts, perceptions, and the state of being conscious.
- Thinking: Thoughts and pensiveness.
- Memory: Capacity to memorize data and remember past events.
- Insight: Capacity for self-knowledge and self-recognition.
- Cognition: Perceiving and conceiving in reaction to stimuli.
- Intelligence: Making a person bright and intelligent.
- Sleep: Dependent on the stability of the Mind.
- Wisdom: Derives from a healthy Heart/Mind; the sagacity to apply knowledge wisely.
- Affections and Feelings: The Mind feels affections and recognizes perception-generated stimuli (taste, temperature, etc.).
- Ideas: Responsible for projects, dreams, and life purpose.
- Senses: Coordination of the sense organs.