Library

Tang Rongchuan stated: Each of the four seasons has its dominant qi (vital energy) and guest qi, with variations in strength across the five directions. What is cited here merely clarifies the principle that the qi of the zang-fu organs should run in parallel with the timing of heaven and earth; physicians are often able to infer other cases from this single example.

The Classics state: In spring, diseases such as rhinorrhea (nasal congestion with discharge) and epistaxis (nosebleed) are prevalent.

Tang Rongchuan explained: Rhinorrhea refers to nasal congestion with discharge, while epistaxis refers to nosebleeds. Rhinorrhea belongs to the Qi level. In spring, Yang qi exerts itself outward; if obstructed by Yin cold, it leads to nasal blockage. Treatment should focus on dispersing cold. Epistaxis belongs to the Blood level. In spring, Liver Wood generates Heart Fire; this fire agitates Blood and rushes upward, invading the clear orifices. Since the nose is the opening of the Lung, Liver-Wood Fire insulting Lung-Metal causes epistaxis. Treatment should focus on clearing and descending fire. "Prone to disease" means frequently suffering from these conditions.

Tu Weisheng commented: Spring lies between winter cold and summer heat. People are most likely to be negligent at this time because the weather is slightly warm, allowing for both slight exposure to cold and slight exposure to heat. Therefore, rhinorrhea and epistaxis are common during this period. Tang Rongchuan’s explanation of epistaxis is particularly insightful.

The Classics state: In mid-summer, diseases of the chest and hypochondrium are prevalent.

Tang Rongchuan explained: The chest, located between the two breasts, corresponds to the Heart. The hypochondrium, located beside the two breasts, corresponds to the Sanjiao (Triple Burner). The Heart is Ministerial Fire (Jun Huo), and the Sanjiao is Assistant Fire (Xiang Huo); both correspond to the summer climate. Thus, in mid-summer, chest and hypochondriac diseases occur because excess Fire often leads to rebellious Qi and fullness.

The Classics state: In late summer, severe diarrhea (dong xie) and middle-jiao cold are prevalent.

Tang Rongchuan explained: In the sixth month of late summer, Damp-Earth qi dominates. The Spleen governs dampness but dislikes dampness; excessive dampness triggers severe diarrhea. When Yang qi reaches its peak on the exterior, it fails to warm and nourish the Middle Earth (Spleen/Stomach), leading to middle-jiao cold. Observing that well water is warm in winter and cold in summer reveals that the middle jiao tends to be cold in summer.

Tu Weisheng commented: This section describes illness arising from heat transforming into cold, whereas the previous section described heat transforming into fire; the two sections form a contrast. Tang Rongchuan’s interpretation is somewhat too rigid regarding seasonal timing, failing to account for human nature and factual reality. Late summer is the hottest time of the year; consequently, people dislike heat most intensely. They often consume fruits and raw/cold foods arbitrarily to resist heat and dryness, seeking physical refreshment. However, internal Yang fire is limited, while external desires are infinite. Daily depletion makes it unlikely that Yang fire would not decline. Once stomach cold is established, food and water cannot be digested, resulting in severe diarrhea and middle-jiao cold. The prevalence of sha syndrome and cholera-like symptoms in summer follows this same logic. If one argues that Spleen governs dampness and dislikes it, so excess dampness causes diarrhea, and extreme exterior Yang fails to warm the Middle Earth causing cold, this implies that human Stomach Yang transforms into cold due to excessive external heat. Yet, our breathing connects purely with external Yang. How could the air we inhale be Yin-cold when external Yang is hot? Therefore, I assert that summer severe diarrhea and middle-jiao cold are entirely due to overconsumption of raw and cold foods. Regarding the observation that well water is warm in winter and cold in summer, this results from the comparison between well water and air; in reality, well water temperature remains constant. It is only because air has temperature variations that our fingers perceive cold or warmth upon contact.

The Classics state: In autumn, wind-malaria (malaria induced by wind pathogen) is prevalent.

Tang Rongchuan explained: Wind corresponds to the Liver, and malaria corresponds to the Shaoyang Gallbladder. Malaria caused by wind is essentially a Wood-Fire pathology. Its prevalence in autumn is due to Wood-Fire insulting Metal. Autumn is when Lung-Metal qi dominates; Metal qi is clear and肃 (solemn/cleansing), causing skin pores to close naturally and interstices (cou li) to harmonize. If wind agitates, preventing pore closure, chills and fever occur. If wind and fire fan each other, interstices fail to harmonize, leading to shivering and dark urine. Understanding this principle allows one to master the treatment of malaria.

Tu Weisheng commented: Wind pathogen affects the flesh layer, while malaria pathogen resides in the interstitial layer. Since interstices are outside the flesh, how can wind cause malaria? It is because the wind pathogen was not fully resolved and instead lodged reversely in the interstices. Formerly, the Yellow Emperor asked Qibo: Wind and malaria are similar and of the same category, yet wind persists constantly while malaria has periods of remission. Why? Qibo replied: Wind qi stays in its location, hence it persists; malaria qi sinks along the meridians and enters inward, manifesting only when Wei Qi (Defensive Qi) arrives. This shows wind is wind and malaria is malaria; one cannot simply deduce malaria from wind. However, Qibo also stated: Injury by cold first, then wind, results in chills followed by heat, occurring at specific times, named Cold Malaria. Injury by wind first, then cold, results in heat followed by chills, also occurring at specific times, named Warm Malaria. Cases with only heat and no chills indicate prior exhaustion of Yin qi, with solitary Yang flare-up, causing shortness of breath, oppression, heat in hands and feet, and nausea, named Dan Malaria. Thus, some malaria cases are wind-induced, others are not; they cannot be generalized. To fully master malaria treatment, one must consult the Malaria discussions in the *Neijing* and the subsequent collection on malaria syndromes and treatments, ensuring thorough understanding to avoid errors.

The Classics state: In winter, Bi obstruction (joint pain) and Jue reversal (cold limbs) are prevalent.

Tang Rongchuan explained: Bi refers to joint pain; Jue refers to cold extremities. If Kidney Yang qi can reach the joints and fill the four extremities, these diseases do not occur. In winter, Cold-Water qi is strong; often, Kidney Yang is insufficient, leading to frequent occurrence of these diseases.

Tang Rongchuan concluded: Diseases of the four seasons are numerous, but these are the most common. By understanding these principles, the mechanisms of all out-of-season diseases can be recognized.