Qi: vital energy which determines our ability to resist, and recover from various diseases. Qi flows through the body along meridians in the same way that blood circulates in the body. It is possible therefore, not only to have a total body deficiency of Qi, but also localised deficiencies and excesses of Qi may occur if there is an obstruction to the flow of Qi in the body.
Yin and Yang. two balancing and opposing qualities. Yang is hot, fire, dry, exterior, energy, active, daytime. Yin on the other hand is cold, moist, female, interior, night-time, soft, inactivity. Since Yin and Yang are opposites, harmony can only be achieved by maintaining balance. Within the body, the interior, the blood and other fluids, and the substance of the body, are all Yin. Disease results if Yang and Yin are unbalanced. For instance, exposure to excessive cold ( too much Yin ) will result in damage to the Yang. Similarly excessive heat and exertion, fever, infections, and fluid loss will damage the Yin. Excessive or inappropriate use of Yang or Yin herbs ( or foods ) will also cause an imbalance condition.
The Five Elements:Water, Fire, Earth, Metal and Wood. Each Element corresponds to a certain bodily organ and to various constitutional strengths and weaknesses.
These have considerable diagnostic significance in Chinese medicine because each of the Elements is related to separate external easily visible bodily parts or organs. Since the Liver is related to the nails and the eyes for instance, Wood ( Liver ) diseases may often be diagnosed by inspecting the eyes and the nails. Additionally, since the Liver is related to the emotion of anger, this also assists in the diagnosis of Wood diseases. It can also be seen from the Correspondences, that the Spleen ( Earth ) is sensitive to Dampness, the Liver ( Wood ) to Wind, the Lungs ( Metal ) to Dryness, the Kidneys ( Water ) to Cold, and the Heart ( Fire ) to Heat.
The Correspondences of the Five Elements also assists in the diagnosis of a person’s constitution.
Since each Element ( organ ) can be more Yin ( cold/ underactive ) or, alternatively, more Yang ( hot/ overactive ), the various Elements also correspond to different manifestations according to whether the organ concerned is overactive or underactive. We may observe either a Wood Yang person or a Wood Yin person. Additionally, although a person may have inherited a particular constitution, it is possible, through the onset of disease, to acquire the features of a different type of constitution. For instance, if a Wood person were to acquire Kidney ( adrenal ) disease then the features of a disturbance in the Water Element may become predominant. Although, in such a case, the underlying type of constitution may in fact remain unchanged, the disease state may tend to obscure the features of the original constitution.