Disharmonies of the Kidney in the body

In Traditional Chinese Medicine (TCM), “kidney” (Kidney) is referred to as the broader “kidney jing.” “Jing,” also known as essence or “jing qi,” is mostly stored in the kidneys and is the most basic substance that constitutes the human body and maintains physiological activities. It includes the vital essence inherited from parents—the innate essence—and the acquired essence of nutrition obtained through food, drink, and respiration.

The Kidney stores of Jing are the "foundation of life", the source of bodily reproduction, development and maturation; Kidney disharmonies are often, therefore, the cause of reproductive problems, developmental disorders and premature aging. The Kidney serves such functions as regulating hormones and the immune system, controlling internal fluid flow, and managing mental health. Jing produces Marrow; the Kidney energy field includes the anatomical kidneys and the bones and is responsible for creating and supporting the bones and teeth. The body can never have too much Jing, so patterns of Kidney disharmony tend to be ones of Deficiency. 

Kidney deficiency does not necessarily imply a problem with kidney function in the conventional sense. In Chinese medicine, the concept of Kidney encompasses a broader scope, including the bladder, kidneys, lower back, lower limbs, uterus, ovaries and the reproductive system, collectively known as the Lower Burner. TCM categorizes the body’s energy into yin and yang, with the kidneys serving as the central hub of yin and yang balance. Kidney deficiency is further classified into two types: kidney yang deficiency and kidney yin deficiency.

Because the Kidney is considered the root of the Yin and Yang of all the Organs, disharmonies of the Kidney are most often linked to those of other Organs.

Kidneys rule the 'grasping of the Qi'. The Kidney acts together with the Lung in enabling the deep penetration of inhaled air and energy into the body. Hence the Kidney is also called the "root of Qi". Kidney disharmony may result in respiratory problems, notably chronic asthma.

The Kidney is the Yin Organ of the element Water. It is paired with the Yang Organ of Water, the Bladder. The functioning of Kidney are therefore vital to the Water cycle of the body; in this role it works together with the Spleen and Lung. The specific role of the Kidney is to purify the Water it receives from the Lung, Small Intestine and Large Intestine and excrete the impure. Dissonance in the Kidney may also show up as respiratory problems of the asthma type, hearing difficulties (the sense organ of the Kidney is the ear) and hair conditions.

Because the Kidney is responsible for the ionic balance of the Blood, there is also a close connection between the functioning of the Kidney and the nervous system. Here Water and Fire act together, the latter in the coordination of electrical impulses. Ancient texts distinguish Yin-Kidney and Yang-Kidney. The Yin-Kidney is also called the Water-Kidney and the Yang-Kidney the Fire-Kidney. The Water-Kidney filters the Blood and produces urine, corresponding to the functions of the anatomical kidneys. The Fire-Kidney corresponds to the endocrine system: the adrenal glands, sex glands, islets of Langerhans in the pancreas, thyroid and thymus glands and the pituitary gland.