The theory of Yin and yang is the basis of the old Chinese philosophy. Yin originally means dark side of the mountain and yang means the sunside. On the body the yang meridians are on the side that is normally in the sun (the back) and the yin meridians are on the shadow side (the front).
Yin and yang are manifested everywhere and all movement and changes are in between them. These movements we call 'life'. We use the words yin and yang to describe this life. Yin and yang are no definitions, but a method to describe changes. A man is more yang than a woman. But a young woman is more yang than an old woman. Yin and yang describe relationships. There is no absolute yang or absolute yin.
A few characteristics of yang and yin are:
Yang: heaven, male, energy, light, warm, summer, active, salt.
Yin: earth, female, matter, darkness, cold, winter, passive, sweet.
Yin and yang organs
The yin organs are: lung, spleen, kidney, heart, liver.
The yang organs are: large intestine, stomach, bladder, small intestine and gallbladder.
The yin organs are filled with blood. Lung is an exception, but this organ is surrounded with blood. The yin organs are of vital importance for the body. Weakness of the yin organs often leads to death.
The yang organs are full of chi. Chi often changes. This means that they are sometimes full and sometimes empty. The yang organs play an important role in digestion. A yang organ can be removed without causing death.
Every yin organ is related to a yang organ with a similarly function.
Lung/large intestine: excretion and inhalation
heart/small intestine: quality of the blood
liver/galbladder: distribute energy.
The 5 elements
The theory of the 5 elements was developed after the theory of yin and yang and is adding something to it. All symptoms in nature were divided into the 5 tendencies, 5 kinds of energy.
These elements are: earth, metal, water, wood and fire. They are related in a creating and a control cycle.
The seasons are for example shown in the creating cycle.
In winter (water) life is directed to the inside;
in spring (wood) everything starts to grow, there is a force upwards;
in summer (fire) everything is flourishing, a radiating force;
in late summer (earth) everything is ripening;
in autumn (metal) forces return to the earth.
The theory and the practice
The theory is a help for the therapist to understand what he or she is observing. The theory is based on observations and not the other way round. Sometimes a person shows exactly the symptoms related to one of the elements. For example a woman is wearing black clothes, complains about cold, feels very tired, likes salt food and has dark bags under the eyes. A problem with kidney meridian is obvious. But often a few elements are involved and diagnoses is more complex. It is important not to fix but to keep an open mind.