The Kidney Essence or Jing of Kidney is the combination of the Pre-Heaven Essence with the Post-Heaven Essence.

That is, it is the combination of the essence inherited from parents stored in the Kidneys from conception, constantly enriched by the essence produced from food, beverages and air.

The Kidney Essence is not only stored but circulates throughout the body thanks to the 8 Extraordinary Vessels.

• Determines growth, reproduction, development, sexual maturity, conception, pregnancy, menopause and aging.

• The cycles of essence are 8 years in men and 7 years in women.

The Kidney Essence represents the Yin of Kidney; The Qi of Kidney represents the Yang.

• Within the Kidneys, Kidney-Qi refers to its Yang aspect or Ming Men.
• Kidney-Yin contains the Jing of Kidney.

Essence is the physical material that when heated by Kidney-Yang and by the Ming Men, results in Kidney-Qi. In other words "Renal Qi is the energy extracted from the interaction between renal Yin and Yang".

Controls growth, development and reproduction until death.

• Before puberty it controls all developmental processes: teeth, bones, brain maturity, etc.
• From puberty onwards: controls fertility and sexual maturity. It is the basis of pregnancy and conception.

Produces the Marrow

Although the concept is slightly different from Western medicine, there is a direct relationship with bone marrow.

For Traditional Chinese Medicine the marrow is a "master" substance (without equivalent in Western medicine) that produces bone marrow and fills the bones and the brain.

• The brain is the sea of marrow.

Constitution

Physical constitution, resistance to external factors and our strength are determined by Kidney Essence.

The Defensive Qi has its root in essence, from which it draws part of its strength.

Three Treasures

The Jing, the Qi and the Shen are considered as the three treasures (physical and psychic substances) fundamental to life.

• Jing and Qi are the basis of shen.
• They represent the three states of Qi condensation: Shen-subtle, Qi-ethereal and Jing-dense.
• The mind depends on Qi and essence: healthy Kidney (Pre-Heaven and Post-Heaven) plus healthy Stomach/Spleen/Lung (Post-Heaven) equals a healthy Heart (Mind).

See: The Pre-Heaven and The Post-Heaven