KIDNEY 8

The concept of mingmen, the vital gate of life, is an integral part of the kidney system. The Nanjing (Classic of Difficulties) elaborated on basic Neijing theory by figuratively differentiating these two aspects of the kidney in structural terms, thereby initiating a medical theory that was later referred to as the mingmen school: "There are two kidney parts. Actually, not both of them are kidneys. The left one is the kidney, the right one is mingmen." The classic then goes on to elaborate that mingmen is the place "where the entirety of bodily jing and shen is at home, and where the original qi is generated." "It is the root of all zang-fu networks, the foundation of the twelve channels, the gate of breath, and the source of all three burning spaces." Later medical scholars argued that mingmen is an immaterial force that could not be physically located in the right kidney. Rather, its location is the central point on the spine between the two anatomical kidneys and opposite the umbilicus, thus forming a "posterior dantian." The Chinese name for the acupuncture point located there is mingmen (GV-4).

The fire lodged within kidney water is often referred to as the body's ministerial fire (xiang huo), as opposed to the imperial fire (jun huo) of the heart. In its role of the "minister" serving the higher centers, it warms the spleen, ripens food, grasps lung qi, and gives volume to a person's voice.

The triple burner, a fu organ that is said to pass through and connect all of the body's three burning spaces, stimulates qi transformation with a specific focus on water metabolism. It keeps the body's water ways unobstructed and smoothly operating. These functions of the triple burner are intimately tied to the kidney and bladder. The Neijing says: "The upper burner is like a mist, the middle burner is like a swamp, and the lower burner is like a ditch," referring to the essence misting activity of the lung on top, the fermenting action of the spleen/stomach at the center, and the canalization of water in the lowest part of the torso.

Injury to Kidney (Yin) and Mingmen (Yang) Fire: if the kidney's ability to store jing becomes disturbed, a person's growth patterns and reproductive ability will be affected; infertility, hair and tooth loss, slow physical development, or softness and malformation of the bones may result. 

If within the kidney jing the crucial controlling/generating balance between kidney yin and kidney yang becomes disturbed, different symptom patterns may arise. Typical manifestations of hyperactivity of yang due to kidney yin deficiency are burning sensation in the palms and soles, tidal heat sensations, night sweats, spermatorrhea, or sexual dreams. When the kidney yang is exhausted and thus unable to execute its ministerial warming function, symptoms of listless spirit may result: sore lower back and knees; cold sensations in the body and its extremities; inhibited urination or frequent and profuse urination; early morning diarrhea; asthmatic panting upon slight physical exertion; difficult breathing; impotence and premature ejaculation; or infertility due to a "cold uterus." If there is evidence of kidney deficiency without obvious cold or heat symptoms, this symptom complex is usually referred to as kidney qi (or kidney jing) deficiency. 

It is important to understand the intimate relationship of kidney yin and kidney yang, and that prolonged kidney yin deficiency will eventually influence kidney yang and vice versa. This phenomenon is usually called a deficiency of kidney yin implicating kidney yang, or a deficiency of kidney yang implicating kidney yin.

Changes in Water Metabolism: since the kidney is said to be in charge of water, all pathological changes involving water are in some way associated with the kidney. If there is a lack of kidney yang, the body's general process of qi transformation will suffer, and consequently water metabolism will be inhibited. As the Treatise on Blood Diseases (Xuezheng Lun) explains: "If there is not enough yang qi, pathological water accumulations will turn into phlegm and distress the heart or attack the lung, or cause symptoms of edema, abdominal pain accompanied by a sensation of qi rushing upwards, or diarrhea and intense cold." 

Most cases of phlegm or edema occur when the yang fire is unable to transform yin water. Figuratively speaking, the kidney is the general commanding the two water fu organs which are mainly involved in the transportation and transformation of water, namely the triple burner and the bladder. As the Neijing says: "The shaoyang [triple burner] belongs to the kidney; above, the kidney connects with the lung, and thus has two fu organs under its command [triple burner and bladder]." 

Therefore, if there is not enough kidney yang, the upper burner cannot properly distribute fluids, the middle burner cannot properly steam and ripen food and separate the clear from the turbid, and the lower burner cannot properly transform qi, thus influencing the opening and closing ability of the bladder (causing excessive or inhibited urination, as in bed wetting, frequent urination, nocturia, etc.). 

Moreover, since urine is manufactured from body fluids which are in part produced by the kidney, a deficiency of kidney water will always involve a deficiency of fluids, causing inhibited urination. Along the same lines, too much urination will eventually harm the body's fluid supply. 

Emotional Influences on Proper Kidney Function: the kidney is said to house the force of will power and determination. Will power, therefore, relies on nourishment by kidney jing. If jing is weak, then will power and its sustained expression (memory) will also be weak. 

Intense or prolonged fear, the emotion associated with the kidney, will cause injury to the kidney qi, resulting in impotence, spermatorrhea, or the gradual development of cowardly behavior. The other way around, a physical deficiency of kidney jing can cause a disposition for panicky and fearful behavior. 

Kidney Disorders Causing Pathological Changes in the Bones, the Marrow, the Hair, and the Ears: if kidney jing is sufficient, the continuous production of high quality marrow is assured, resulting in properly nourished and, thus, firm and strong bones. Otherwise the skeletal structure will be weak, or structural changes such as osteoporosis might occur. 

If the kidney is harmed by pernicious qi affecting the kidney jing and consequently the marrow and bones, there will be symptoms of weak and sore waist and legs, or even atrophy of the legs causing severely limited mobility. As the Neijing states: "If kidney qi is pathologically hot, the lumbar spine will be inhibited, the bones will become brittle and the marrow scorched, and atrophy of the bones will result." 

For the same reasons, symptoms of loosening and deteriorating teeth, or the drying, greying, and gradual falling out of hair are related to the state of the kidney's jing qi. Since the ears and the associated sense of hearing also depend on nourishment by the kidney's jing qi, ringing in the ears, loss of hearing, or deafness are typical symptoms for various aspects of kidney deficiency.