“The Kidneys store the Jing” is one of the stated functions of the Kidneys in Chinese medicine. The term Jing is one which has no English language equivalent. It refers to a substance which is endowed to each person, through their parents, at the moment of conception. It has both a qualitative and a quantitative component, is finite in quantity, and is stored in the conceptual space of the lower dan tian (literally “elixir field”) between the Kidneys. It gives root to the Yin and Yang, the fundamental substrates out of which all bodily substances and processes arise (see A Brief Introduction to Yin and Yang).
Jing is like one’s life force. In terms of usage, it works like this. Each day we produce Qi, out of the transformed essence of food, drink and air. This is done by the Spleen and the Lungs. It is the Spleen which finally makes Qi. At the end of the day, if we take in more Qi than we expend, we store the excess as post-natal Jing. Post-natal Jing can be utilized when Qi supplementation is necessary. But if we deplete both our Qi and post-natal Jing, then we must utilize our pre-natal Jing (referred to as simply Jing). This gradually weakens or life force. Jing is irreplenishable. When it is used up, we die. Jing is depleted by prolonged overwork, stress, and poor diet.
Qi is associated with the Spleen. Jing is associated with the Kidneys. To complete the story, Shen is associated with the Heart. Shen means spirit, as in the spirit you see in someone’s eyes. Shen is an accumulation of Qi and Jing in the Heart. Jing, Qi, and Shen are referred to as the Three Treasures in Chinese medicine. They are vital substances which need to be nourished and protected . For more on this topic, see Wisdom – The Virtue of the Kidneys and Menopause is not a Disease.