Qigong

To followers of the yin-yang wuxing theory, everything in the world is either yin, the nagative and feminine force, or yang, the positive and masculine force. The two forces complement and oppose each other. It is not difficult to understand yin and yang, if we think of "the complementary opposites" such as heaven and earth, positive and negative, male and female, life and death.
Wuxing which arises from yin-yang refers to the five elements (wood, fire, earth, metal and water) and their different characteristics. It is said that wood arises from water and prevails over earth; fire arises from wood and prevails over metal; earth arises from fire and prevails over water; metal arises from earth and prevails over wood; water arises from metal and prevails over fire.
The five organs of the human body are compared to the five elements and are said to behave likewise:
Liver (wood) complements the heart (fire) and opposes the spleen (earth); the heart complements the spleen and opposes the lungs (metal); the spleen complements the lungs and opposes the kidneys (water); the lungs complement the kidneys and oppose the liver, the kidneys complement the liver and oppose the heart.
Yin-yang wuxing formulates the theory of the jing-luo -- that the human body contains vertical trunks (jing) and branches (luo) made up of 20 invisible passages, 12 meridians (zhengjing) and eight pulses (qijing). They are different from the nervous system known to modern medical students. These passages are divided into two groups: yin and yang. In each group there are six meridians which extend into four limbs and four pulses which are distributed in the body. The internal ones are called yinyang, and the external ones the yang-jing. These meridians and pulses carry a "life force" through the whole body. If the "life force" cannot flow easily in the passages, the body becomes ill. The balance of yin-yang wuxing is essential for peace, harmony and health. Diseases and ailments of the body occur when the balance of yin-yang wuxing is upset. For instance, if the fire element in the heart is too strong for the metal element in the lungs, the physiological balance cannot be maintained. The dominance of heart over lungs can cause the loss of weight, general lassitude, and a pain in the chest. Qigong breathing exercises can help restore the balance.
Since these passages are anatomically invisible, their existence remains a matter of dispute. Although the theory seems to "unscientific", its principles are precise and based on a belief that man has a spiritual as well as a physical existence.