TCM believes in both opposite and uniting relationships between both the organs and the tissues and between the human body and its natural environment. These principles can maintain a relative dynamic balance and at the same time a process in which contradiction alternately appears and disappears co-exists. When this dynamic balance is disturbed for whatever reason and cannot immediately be restored through self-regulation, this loss of balance opens the door to certain diseases.
The Influence of the Five Elements
TCM identifies etiological or causal factors in the appearance of certain diseases. These pathogenic influences alter the state of relative balance in the body.
The modern Western medical diagnostic approach is to isolate purely physical factors as the cause of disease. These can be bacteria and viruses, chemical compounds, and other external factors are blamed for most illnesses. They are not wrong as a compound can poison you. Do not confuse this with diseases. The Chinese, however, view many of these "causes" merely as symptoms of the disease; because a certain organ is weak and unable to resist outside invasion, it is unable to attack by an outside agent. Killing or eliminating the agent stops the immediate symptoms of the disease. TCM also restores the original Qi (vital energy) of the diseased organ and tissues because it is only a matter of time before it would succumb to another attack.
Asian medicine attributes the cause of most diseases to external cosmological and internal emotional factors. These factors conform and act according to the principles of Yin-Yang and the five elements, which both stress balance and interconnectedness.
What are the “Six Evils?” They are external cosmological causes of disease which are governed by the meteorological conditions of season and climate. It also accounts for the internal emotional factors called the "Seven Emotions" which are affected by our emotional response to different situations.
The Huang Ti Nei Ching (The Yellow Emperor's Medicine Classic) states: "The pathogenic evils either originate in Yin or originate in Yang; those coming from Yang are related to wind, rain, cold, and summer heat; those coming from Yin are related to food and drink, living places, sexual life, and emotions such as joy and anger."