The human body is composed of various systems, each with different structures and functions, which are interconnected. When one system is affected by a virus, it can transmit to other systems, leading to comorbidities. Each system operates on a common assembly line; if one system malfunctions, it can cause the entire body to be out of balance. There exists a relationship of mutual influence and restraint among various systems, which is the essence of the Five Elements theory in Traditional Chinese Medicine (TCM). The Five Elements relationship encompasses the concepts of mutual generation (相生, xiāng shēng), mutual restraint (相克, xiāng kè), and shared attributes.
The kidneys (肾, shèn) belong to the Water element, while the liver (肝, gān) belongs to the Wood element. According to the Five Elements theory, Water generates Wood; thus, kidney Water is the mother of liver Wood. If the kidneys are diseased, it will inevitably affect the liver, leading to what is termed kidney-related liver disease (肾性肝病, shèn xìng gān bìng). The treatment for kidney-related liver disease should primarily focus on the kidneys while also addressing the liver.
The liver Wood restrains the spleen Earth (脾土, pí tǔ), indicating an antagonistic relationship. This means that a strong liver can weaken the spleen. Under normal circumstances, the liver must restrain the spleen so that the spleen can properly transform food. However, under certain conditions, if the spleen becomes strong and the liver weakens, the spleen will hinder the liver, making it difficult for liver Qi to flow, which can lead to liver disease caused by spleen issues (脾性肝病, pí xìng gān bìng). In TCM, the spleen refers to the digestive and absorption system, and treatment for spleen-related liver disease should primarily focus on the spleen while also addressing the liver.
The liver Wood generates heart Fire (心火, xīn huǒ). In TCM, the heart (心, xīn) refers both to the physical heart and the mind. A weakened heart Fire will inevitably affect the liver; thus, if there are heart issues, the treatment should primarily focus on the heart while also addressing the liver to ensure both can thrive together. If only the liver is treated without addressing the heart, the liver may become strong while the heart condition remains unresolved, leading to new complications.
The lung Metal (肺金, fèi jīn) restrains the liver Wood. When the lungs are strong, they can restrain the liver, preventing it from becoming overactive. However, if the lungs are weak, they cannot restrain the liver, leading to liver hyperactivity. If lung Metal becomes excessive, it will overly restrain the liver, causing liver Qi stagnation. Liver disease caused by lung issues (肺性肝病, fèi xìng gān bìng) should primarily focus on treating the lungs while also addressing the liver. If only the liver is treated without addressing the lungs, the liver disease will worsen.
The lung Metal restrains the liver Wood, with kidney Water (肾水, shèn shuǐ) in between. Metal generates Water, and Water generates Fire. By centering on kidney Water, we can harmonize lung Metal and liver Wood, reducing their antagonistic energies and promoting coexistence. If kidney Water is deficient and cannot take charge, the antagonism between lung Metal and liver Wood will arise, similar to a ruler who is incapable, leading to conflict among the ministers. The liver Wood, deprived of the nourishment from Water, will succumb to lung Metal. If the liver Wood is excessively restrained, it can lead to liver disease, which should be treated primarily by tonifying kidney Water while also addressing lung Metal. If the liver Wood is not treated, the liver disease will persist. Incorrectly using Chai Hu (柴胡, chái hú) to purge the liver will exacerbate the condition. Using Bai Shao (白芍, bái sháo) to nourish the liver is ineffective if the liver Wood is restrained by lung Metal, as this will lead to stagnation of Wood Qi and ultimately harm the liver.
The liver Wood restrains the spleen Earth, with heart Fire in between. Heart Fire is the mother of spleen Earth, while liver Wood is the mother of heart Fire. By centering on heart Fire, we can harmonize the liver and spleen, reducing their antagonistic energies to promote peaceful coexistence. If heart Fire weakens, the spleen Earth will lack nourishment, and excessive liver Wood will overly restrain the spleen. The spleen is the foundation of postnatal health; if it is excessively restrained, it will lead to poor digestion and absorption, resulting in nutritional deficiencies in the liver and other systems, leading to a multitude of diseases. Therefore, liver disease arising from these issues should primarily focus on treating the liver while also supporting the spleen and heart Fire.