Traditional Chinese Medicine (TCM) emphasizes identifying the cause through pattern differentiation and treating based on the cause. "Pattern" refers to the syndrome or pattern of disharmony, representing the macroscopic state of the body at a given time (such as the weather being cloudy, clear, windy, or rainy). Behind each pattern lies a set of causative factors and pathological mechanisms, along with the symptoms they induce. TCM focuses on treating the pattern rather than directly addressing the symptoms. A pattern reflects a cross-section of the entire disease progression, representing a temporary state or model of the complex human system. The treatment principles in TCM are primarily based on this. The progression of a disease can be viewed as a sequence of various patterns.

The establishment of various pattern names represents certain typical models, facilitating learning and clinical practice. However, clinical presentations are often complex combinations of typical patterns, and can vary infinitely. Therefore, one should not rigidly adhere to existing pattern classifications but must learn to grasp the underlying laws and essential mechanisms of disease progression to adapt to endless variations. As stated in the Su Wen‧Six Yuan Zheng Ji Da Lun: "Those who understand the essentials can summarize it in a single statement, while those who do not understand the essentials will wander endlessly. This is what it means."