“Exterior-Interior” and “Deficiency-Excess” are important concepts in Traditional Chinese Medicine (TCM). In the Neijing, the term “Exterior-Interior” appears 28 times, while “Deficiency-Excess” appears 60 times. The concept of Exterior-Interior can refer to the surface of the body versus the interior, the Yang meridians versus the Yin meridians, or the relationship between the exterior and interior. It is one of the frameworks for analyzing and examining issues. The Suwen: Jin Kui Zhen Yan Lun states: “Therefore, those skilled in pulse diagnosis must carefully observe the five zang and six fu organs, one in opposition and one in agreement, the principles of Yin and Yang, Exterior-Interior, and the relationship between male and female. They must understand the intentions of the heart, align the heart with essence, and teach only those who are suitable, and impart only the true knowledge; this is called attaining the Dao.” The Zhu Zhi Jiao Lun also states: “The Emperor said: Good! Do not lose this; these are all interrelated principles of Yin and Yang, Exterior-Interior, up and down, and male and female, which can be understood to know the celestial phenomena above, the geographical conditions below, and the human affairs in between, allowing for longevity and teaching the masses without doubt. The medical principles can be passed down to future generations and can be considered a treasure.” The terms Deficiency and Excess also have different meanings, but the focus is on analyzing the deficiency and excess of diseases and guiding treatment. Observing deficiency and excess can “determine life and death,” and adjusting deficiency and excess can “eliminate pathogenic factors.” Therefore, it is stated in the Liujie Zang Xiang Lun: “Without knowing the years of age, the vigor of Qi, and the origins of deficiency and excess, one cannot be considered skilled.”Liu Gengsheng, Professor at the Institute of TCM Literature and Culture, Shandong University of Traditional Chinese Medicine, Vice Chairman of the Medical History Literature Branch of the Chinese Association of Traditional Chinese Medicine, and Chief Health Science Popularization Expert of the Chinese Association of Traditional Chinese Medicine.
Be cautious in the end as in the beginning, and there will be no failures.