Library

The pathogenic factors latent during winter, suppressed and hidden until spring and summer, are activated by the internal movement of Yang Qi, transforming into heat and reaching outward. This is the warm disease caused by latent Qi (latent pathogenic factor). The *Neijing* (Yellow Emperor's Inner Canon) states: "If one is injured by cold in winter, one will inevitably suffer from warm diseases in spring." It further states: "For those who contract Shaoyang disease and transform into warm diseases, if it occurs before the Summer Solstice, it is called a warm disease; if it occurs after the Summer Solstice, it is called a heat disease." The *Nanjing* (Classic of Difficult Issues) states: "Shaoyang disease encompasses five types, including warm diseases and heat diseases." The *Shanghan Lun* (Treatise on Cold Pathogenic Diseases) states: "In Taiyang disease (a syndrome caused by pathogenic invasion of the Taiyang channel), characterized by fever, thirst, and aversion to cold being absent, this is a warm disease." All these references pertain to warm diseases triggered by latent pathogens.

There is another type of pathogen known as Wind-Warmth. During spring and summer, upon contracting warm winds, the pathogen becomes constrained within the Lung, leading to cough and fever, and in severe cases, manifesting as sand-rash (scarlatiniform rash). What the *Neijing* refers to as "when wind pathogen overflows internally, treat with pungent-cool methods," and what Ye Tianshi (Ye Gui) in his *Wenre Lun* (Treatise on Warm Heat) describes as "warm pathogens enter from above and first attack the Lung," both refer to this type of sudden contraction of Wind-Warmth. Latent Qi emerges from within; therefore, treatment primarily focuses on clearing and purging interior heat. Its clinical manifestations are numerous and complex, requiring simultaneous assessment of the patterns and symptoms of the Six Channels (Taiyang, Yangming, Shaoyang, Taiyin, Shaoyin, Jueyin) to establish treatment strategies flexibly.

Sudden Wind-Warmth involves pathogens specifically located in the Lung; treatment primarily employs pungent-cool dispersing methods. If heat is severe, sweet-cool methods for clearing and resolving are added. The pathways of exterior-interior transmission in this condition differ significantly from those of latent warm diseases, and consequently, the depth and intensity of treatment are also distinctly different. In recent times, physicians have exclusively adhered to Ye Tianshi’s theories, neglecting the study of warm diseases caused by latent Qi. Whenever encountering warm pathogens, regardless of whether they are suddenly contracted or latent, they uniformly apply Ye Tianshi’s mild and superficial pungent-cool methods, prescribing formulas such as Yinqiao San (Honeysuckle and Forsythia Powder) and Sangju Yin (Mulberry Leaf and Chrysanthemum Decoction) at will. Physicians and patients alike favor this convenience, readily accepting it. However, if anyone proposes the theory of latent Qi, they dismiss it as heterodox, remaining ignorant of what latent warm disease entails. Alas! Latent warm disease is a common external contraction ailment, particularly prevalent in the southern regions, not an aberrant condition. Its records exist in classics such as the *Neijing*, *Nanjing*, and *Shanghan Lun*, not constituting heterodoxy. Yet, clinicians find themselves completely bewildered, lacking any diagnostic approach. How can medical practice be considered competent under such circumstances?