Treat Shaoyin Cold Damage (Shaoyin Taiyang Cold Damage), where the patient's mouth feels neutral (no bitter or dry taste), with aversion to cold in the back, accompanied by fever, fatigue, spontaneous sweating, and thirst. The pulse at both the Cun (inch) and Chi (cubit) positions is deep (Chen) and tight (Jin).

Ephedrae Herba (Mahuang, 麻黄) [removed nodes], Asari Radix (Xixin, 细辛), Aconiti Lateralis Radix Praeparata (Fuzi, 附子) [processed, skin and umbilicus removed, each half tael].

Grind the above herbs into a coarse powder. Take four qian per dose, add one and a half zhan of water, decoct until seven parts remain, strain, and take before meals. If there is coldness in the hands and feet, remove Ephedrae Herba (Mahuang, 麻黄) and Asari Radix (Xixin, 细辛), and add Zingiberis Rhizoma (Ganjiang, 干姜) half a tael and Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) one fen. Alternatively, if there is dryness in the mouth and tongue with thirst, urgent purgation should be employed.

Cold Damage affecting the Foot Jueyin Liver Meridian presents with irritability and fullness, fever with aversion to cold, alternating chills and fever resembling malaria, or retraction of the scrotum, and acute pain in the lower abdomen. The pulse flow and distribution are similar to those of Wind Injury. (This treatise recommends using Xiaojianzhong Tang, see the Nine Pains section; removing Yuanzhi from that formula yields this prescription.)

Treat Jueyin Cold Damage characterized by irritability and fullness, fever with aversion to cold, alternating chills and fever resembling malaria; or retraction of the scrotum. This condition is primarily indicated when the pulses at both the Cun and Chi positions are faint and slow (Wei Huan). If the pulse is deep and short, the scrotum will certainly retract, and Da Chengqi Tang should be used urgently for purgation; this can save one life out of five fatal cases. Chengqi Tangs are medicines that benefit the Yangming channel. However, when the disease reaches Jueyin, the condition is already severe. Since the Yangming channel nourishes the Zongjin (general tendons/genitals), and is attacked by heat toxicity, using Chengqi Tang to purge Yangming heat preserves the function that nourishes the Zongjin. Thus, benefiting Yang to rescue Yin is employed. This concept is analogous to "borrowing a path to conquer Guo" or "besieging Wei to rescue Zhao."

Cinnamomi Cortex (Guixin, 桂心) [four qian and one zi], Paeoniae Radix Alba (Shaoyao, 芍药), Ephedrae Herba (Mahuang, 麻黄) [removed nodes], Armeniacae Semen Amarum (Xingren, 杏仁) [twelve seeds, skin and tips removed], Glycyrrhizae Radix et Rhizoma (Gancao, 甘草) [roasted, each half tael].

Grind the above herbs into a coarse powder. Take five qian per dose, add one and a half zhan of water, decoct until eight parts remain, strain, and take before meals; decocting with fresh ginger and jujube is also acceptable.

Da Chengqi Tang (See Foot Yangming Meridian section)
Xiaojianzhong Tang (See Nine Pains section)

The *Neijing·Re Lun* discusses Cold Damage stating: The Taiyang meridian is the master qi of all Yang meridians; Cold Damage must begin with the Taiyang meridian. By the time of the Han dynasty physicians, all external causes were termed Taiyang Disease, which did not fully elucidate the true principles. The Foot Taiyang Bladder Meridian belongs to Cold Water, its position corresponds to the Earthly Branch Chen. Chen is the origin of the transformation of the Six Qi. Therefore, in Bing-Xin years, the cycle starts at Wu-Zi, and upon reaching Chen, it becomes Ren-Chen Water, where the primary transformation of Taiyang resides. In Heaven it is Cold, on Earth it is Water. Cold favors returning to Water, so Cold inevitably injures the Taiyang first. By analogy, since Cold enters via Taiyang, Wind should enter via Shaoyang, and Dampness via Yangming. The Classics state: "Yin serves as the master, Yang provides the regulation." Distinguishing from Yang reveals the origin of the disease; distinguishing from Yin reveals the timing of death or survival. This is what is meant. One might ask, what is the order of transmission? Although the circulation of Yin and Yang and the sequence of entry and exit have fixed theories, once the disease takes hold, it may favor entering certain meridians, become deficient, become a Lianggan syndrome (simultaneous involvement of exterior and interior meridians), or remain confined to one meridian. How can these be rigidly constrained? One should only treat based on differentiating Yin/Yang, Exterior/Interior, and Excess/Deficiency through pulse and symptom analysis, and certainly not limit the course by days.