The functions of the Kidneys, or the ‘Root of the Pre-Heaven Qi’ is mainly storing Essence/Jing which encourages the physiological developments within the body. The Kidney Yin and Yang are the base for the Yin and Yang of all other Yin organs in the body; the Lungs, Heart, Liver and the Spleen. The Five Elements register the Kidneys as the element of Water, but are also considered the source of the Fire of the Gate of Life or the ‘Ming Men’.

Storing Essence

Parents create the Essence of the Kidney and when food is consumed, Qi is replenished

  1. The Pre-Heaven Essence sustains the fetus and encourages development procedures within the body, including the sexual reproduction and the menstrual cycle. Menstrual Blood, also known as Tian Gui, stems from the Kidney; a lack of Essence from the Kidney causes the underdevelopment of children and infertility or impotence.
  2. They store the refined Essences from refined foods as the Post-Heaven Essence.

The Kidney Essence is a hereditary energy that interacts with the Post-Heaven Essence to be nourished. The Essence is stored and transported through the Eight Extraordinary Vessels.The Kidney Essence transforms Yin to Qi through the evaporation of Kidney-Yang.

Governing Reproduction and Development

The Kidney-Essence controls hormonal changes and reproductive cycles. The decline of the Essence causes the organism to age. If the Essence is weak, the Kidney will also be weak, so the organism will suffer through infertility and loss of sexual power. 

The Yin-Essence of the Kidney is represented by Water, associating to the sperm in males and ova in females. The Yang-Essence of the Kidney is represented by the Fire of the Gate of Life that warms the Uterus for the stability of sexual functions. When the Fire declines, the Kidney Essence in the body’s reproductive organs turn cold, decreasing fertility in both genders and minimizing sexual desire in women.

Ming Men: The Gate of Life

The Kidney counts as 2 organs, the left representing the Kidney and the right representing the Gate of Life or the ‘Ming Men’. The Ming Men is between both kidneys and has both Water and Fire elements that determine life and death. The Fire from the Gate of Life, or the ’Minister Fire’, provides heat for physical functional activities of the body and Kidney Essence.

The Ming Men can extinguish and produce Water. The Gate of Theory differs from that of the Five Element Theory where the Heart is the source of the Fire within the body. However, they could be distinguished since the Heart is the Emperor Fire and the Kidneys represent the Minister Fire. If the Fire declines, the organs will not function properly and the body will lack stability, visible through a constant tiredness, negativity and cold. 

The Spleen needs the heat to transport food Essences and the Stomach needs it to decompose food. The Heart houses the mind and receives Heat, so the Gate of Life influences the stability of the mental state. In Deficiency, the Heart’s function to house the Mind is heavily impaired leading to depression and in excess, the Fire harasses the Heart and the Pericardium. The Lung-Qi needs heat to descend. If it rebels upward, the congestion in the chest could cause breathlessness or asthma and sometimes even chronic asthma.The Liver uses it to move Qi smoothly, the Intestines uses it to transport food and excrement, the Gallbladder uses it to secrete bile and the Triple Burner uses it to cycle through fluids.

The Gate of Life allows the transformation of the fluids in the Lower Burner and if the functions were impaired it could lead to Dampness and Oedema

The Production of Marrow, Will-power and The Control of Bones

The Kidney Essence aids in producing Marrow or Sui, which includes Bones, Bone marrow, the Brain and the Spinal cord. The fats consumed are the material manifestation of Qi that fill the cavities of the Bones and tonifies the Brain, Marrow and the thighs.

The Brain and Spinal Cord are the Sea of Marrow since the Kidney produces the Marrow that makes up the Spinal Cord and fills the Brain. The Kidneys produce a strong concentration by nourishing the Brain. They also determine Will-power, or the Zhi, meaning the determination to reach goals. In weakness, one will stray away from goals that connect to mental depression. 

The Kidneys govern Bones and Bone marrow, which are the Fu or the organ of the Marrow. The Bones will be fragile and teeth become loose in weakness; Pigeon chest could become apparent in children due to poor development. In Heat, the Spine curves and the Bones start to wither. Essence declines in menopause so the Bones become brittle leading to potential osteoporosis.

Governing Water

1. The Kidneys regulate urination in the Lower Burner. In Kidney-Yang Deficiency, the Kidneys will open more than usual causing profuse and pale urination, but in Kidney-Yin Deficiency, they will close more than usual causing scanty and dark urination.

2. The Kidneys send Qi to the Bladder to store and transform urine, and they then excrete it.

3. The Kidney-Yang aids the Intestinal functions in separating clean and dirty fluids.

4. The Kidneys receive fluids from the Lungs to vaporize them for moisture or to excrete them. 

The Ears, The Hair and Spittle

The Kidneys open via the ear: In weakness, hearing is weak and may develop into tinnitus. The Essence from the Kidneys nourishes the hair, providing it with a healthy gloss and thick appearance. In weakness, however, hair will be brittle, may fall out, and may turn grey. Spittle is the thick fluid substance within the back of the mouth that moistens the Kidney and the Kidney Essence. Spitting deprives the Kidney Essence from moisture.

Controlling the Lower Orifices

The Kidneys control the Urethra, spermatic duct and the rear orifice of the anus and any disruption could cause leakage. Weak Kidney energy causes urine to leak out through the urethra which may lead to incontinence or enuresis. Kidney-Qi weakness causes diarrhea and prolapse in the anus. In the event of Kidney Qi deficiency spermatorrhoea may occur within the spermatic duct.

The Original Qi

The Essences of the Kidney and the Fire from the Gate of Life create the Original Qi that makes blood. If the Fire is deficient, the Original Qi will be deficient and so will the blood it produces. The functions of the Kidneys-Yang help Qi transform within the lower abdomen depending on the heat of the Gate of Life. If the Fire is deficient, the Kidneys will be unable to connect the Original Qi with the Gathering Qi from the chest: it will become apparent in problems of breath, the oppression of the chest and cold hands.

The Senses and The Kidneys

The sound of Kidney instability is groaning. The smell of Kidney deficiency is the putrid smell of stagnant Water, mainly in the elderly. In deficiency, the Kidneys produce dark colors. Kidney-Yin deficiency produces dark grey colors on the cheeks or below the eyes, but Kidney-Yang deficiency produces dark bluish colors.

The salty taste, though rare, indicates Kidney deficiency of either Yin or Yang. Moderate amounts of salt aids the Kidney: It’s recommended by some doctors to drink prescribed Kidney Yin tonic tablets with salted hot Water. Cold climate can affect the Kidneys if skin surrounding the area is exposed. Cold in the Kidneys may cause abdominal pain, diarrhea, painful periods or lumbago. The cold injures the Yang and could lead to its deficiency. 

Dreams

In weakness, dreams include Water, either swimming in shipwreck or plunging into Water and fear during the winter. In excess, the dreams include the body detaching from the Spine.