This is a flexible method for treating Shanghan (Cold Damage Syndrome). If swallowing is difficult when eating, it indicates that the pathogenic factor is not in the Stomach; if there is no desire to eat due to clouded consciousness, this is also the case. Since the heat pathogen is not in the Stomach, mistakenly using Chengqi Tang (Cinnamon Twig and Rhubarb Decoction) to purge will inevitably lead to death.

According to the theory of *Shanghan Lun* (Treatise on Cold Damage), pathogens typically transmit through the Foot meridians. Extending this logic to the Hand meridians reveals the secrets of disease mechanism. This generally occurs because pathogens accumulate over time, causing excess in the Foot meridians and deficiency in the Hand meridians, resulting in constrained heat. Transmission may result from errors in sweating or purging methods, or from emotional disturbances and fatigue. Generally, transmission to the Hand meridians has specific causes, which is why ancient physicians developed methods such as Rescue Ni (Correcting Deviation) and Reviving Pulse. These methods not only address the condition accurately but also establish principles for future generations.

Shanghan diseases usually originate from Wind-Cold pathogens. Initially located in the Exterior, if the pathogen enters the Interior, it cannot dissipate spontaneously. With proper warming and covering, spontaneous resolution is possible. Before attempting internal clearance, one must first release the Exterior; only then can purging be considered. If the Exterior is resolved but internal stagnation remains, unless there is significant fullness, chills and fever will persist, and the disease will not be cured. However, if the Exterior is resolved and internal stagnation presents with significant fullness, solid accumulation, hardness, and dry feces, purging is appropriate. Even if four or five days have passed, this will not cause harm. Conversely, if purging is inappropriate and forced, it leads to internal deficiency, allowing heat to enter and combine with cold, causing diarrhea, irritability, and numerous other complications. Mild cases become severe, and severe cases may result in death.

When Yang is excessive and Yin is deficient, sweating leads to death, while purging leads to recovery. When Yang is deficient and Yin is excessive, sweating leads to recovery, while purging leads to death. Thus, how can potent emetics like Shendan (Divine Pill) be misused for sweating? How can drastic purgatives like Kansui (Kansui Root) be recklessly used for attacking excess? The treatments for deficiency and excess are opposites, leading to outcomes separated by thousands of miles. The difference between life and death hinges on a moment. Observing the patient's entire condition leaves no time to count days. Once Guizhi Tang (Cinnamon Twig Decoction) is ingested, excessive Yang leads to death; once Chengqi Tang enters the Stomach, excessive Yin leads to demise. Life and death depend on an instant. Observing the whole body leaves no leisure to calculate days. This represents the interlacing of Yin-Yang and deficiency-excess. The signs are subtle, yet the consequences of reversing sweating, vomiting, and purging methods are swift. Physicians with shallow knowledge, ignorant of the disease source, treat erroneously, causing patients' deaths, yet claiming their actions were correct, until vengeful spirits fill the underworld and corpses litter the wilderness. Would not benevolent scholars grieve upon witnessing this?

For Lianggan Bing (Simultaneous Taiyang and Shaoyin involvement), treatment priorities differ: releasing the Exterior and purging the Interior are distinct. Yet, misguided practitioners claim that mixing Shendan and Kansui can simultaneously resolve the Exterior and clear the Interior. Although the rhetoric sounds clever, the principle violates medical logic. What the wise do, the foolish mimic. If this method truly determined safety and danger so quickly, would it not be miraculous? Most people pursue worldly glory, ignoring impending disaster. Only the enlightened protect the root, taking examples from themselves without needing to look far.

When administering sweating therapy, decoctions should be taken warm. Although instructions say three doses daily, if the condition is severe and unrelieved, intervals should be shortened, completing three doses within half a day. If symptoms conflict with the treatment, monitor closely. For severe cases, observe throughout the day and night. If symptoms persist after one dose, continue with the same decoction. Some patients may require three doses before sweating occurs; failure to sweat indicates a fatal prognosis. After taking Guizhi Tang, if profuse sweating occurs with a surging pulse, administer Guizhi Tang again according to previous methods. If half a day later, vexation returns with a floating and rapid pulse, sweating may be induced again. (*Huo Ren Shu* states: If symptoms persist after sweating, two or three sweating sessions within three days are permissible, aiming for perspiration from waist down. Caution is required; do not act rashly.) Stop medication once the disease is addressed; do not necessarily complete the full course. The same applies to vomiting and purging therapies.

Xu Xicheng recorded a case: A villager had Shanghan with fever, constipation, vexation, thirst, and dizziness. The physician used Radix Crotonis Fructus (Badou, Castor Bean) to purge. The patient soon had loose stools, but the illness remained unchanged. I observed that Yangming heat was bound internally, requiring Da Chaihu Tang (Major Bupleurum Decoction) or Chengqi Tang. Badou only removes accumulation but cannot cleanse toxic heat. I urgently prescribed Da Chaihu Tang. After three doses, the patient sweated and recovered. Zhang Zhongjing’s 113 formulas include only five pills: Lizhong Wan, Xiongxiong Wan, Didang Wan, Wumei Wan, and Maren Wan. Lizhong, Xiongxiong, and Didang pills are large (like marbles), boiled and taken like decoctions. Maren Wan for Pi Yue (Spleen Constraint) and Wumei Wan for damp dysentery use small pills to reach lower areas. Other formulas for expelling toxins, breaking masses, moving blood stasis, or moistening dryness rely on decoctions. It is unheard of to use small pills of Badou to purge pathogens. If purging fails to resolve the disease, adding Radix et Rhizoma Rhei (Dahuang, Rhubarb) and Natrii Sulfas (Mangxiao, Mirabilite) further damages healthy Qi.

In any disease, whether treated by sweating, vomiting, purging, or fluid loss, if Yin and Yang achieve self-harmony, the disease will heal spontaneously. (Severe fluid loss prevents sweating, so healing depends on natural restoration of balance.) In Taiyang disease, if after three days of sweating, vomiting, purging, or warm needle therapy the condition persists, it is termed "Huai Zheng" (Damaged Syndrome). Guizhi Tang is no longer suitable. Observe the pulse and symptoms, identify the error, and treat according to the current presentation.

Zhu Gong stated: Diseases under three days can be treated by sweating; those over three days by purging. This is a generalization. Patients vary in deficiency and excess, and pathogen transmission speeds differ; one cannot rigidly adhere to day counts. Zhang Zhongjing said: Many days with exterior signs and a floating pulse still warrant sweating; few days with interior signs and a sinking pulse warrant purging. Treatment must follow the pulse. Furthermore, Six Qi pathogens enter meridians based on weakness: back exposure affects Taiyang or Shaoyin; face exposure affects Yangming. Not all begin in Taiyang. Cold pathogens may stay in one meridian or spread to others. Treatment depends on pulse and external signs—this is flexibility. For example, a floating pulse with stiff neck, headache, fever, and aversion to cold indicates Taiyang involvement, regardless of duration. Other meridians follow similar patterns. Generally, Shanghan treatment relies on pulse and signs. If days pass but the pulse remains floating and rapid, though weak upon pressure, it still relates to Taiyang and can be cured by sweating. If firm upon pressure, sweating is fatal; purging is required. If initial pulse is sinking, fine, and rapid, with abdominal fullness, dry throat, or thirst, heat is interior, and purging is curative. Without these signs, if there is exterior heat but a sinking pulse, mistaken purging is fatal; use Ma Huang Fu Zi Gan Cao Tang (Ephedra, Aconite, and Licorice Decoction) or Ma Huang Xi Xin Fu Zi Tang (Ephedra, Asarum, and Aconite Decoction) for mild sweating. These are Zhongjing’s definitive teachings.

Dai Yuanli emphasized distinguishing Exterior and Interior for sweating and purging. Spontaneous sweating or diarrhea differs from iatrogenic induction. Sweating should be early; purging late. However, patients with blood loss or stranguria should not be abruptly treated with exterior-releasing agents; gradual resolution is needed. Forced sweating depletes fluids, causing myriad complications and premature death. One cannot simply say "sweating is early." Conversely, Yangming with profuse sweating, Shaoyin with diarrhea and thirst, and Jueyin with curled tongue and retracted testicles require urgent purging. Delaying purging allows heat toxicity to deepen, becoming incurable. One cannot simply say "purging is late."

Li Dongyuan stated: Shanghan treatment prioritizes Exterior/Interior and urgency. For Three Yang diseases, Exterior requires urgent treatment, Interior slow; for Three Yin, Exterior slow, Interior urgent. Floating pulse warrants sweating; sinking pulse warrants purging. Floating pulse with urgent sweating and slow purging indicates Three Yang Exterior. Sinking pulse with urgent purging and slow sweating indicates Three Yin Interior. Ma Huang Tang is "urgent sweating"; Ma Huang Fu Zi Xi Xin Tang is "slow sweating." *Neijing* says "steeping the form to induce sweat" refers to slow sweating (Exterior of Interior). "Releasing what is in the skin" refers to urgent sweating (Exterior of Exterior). Urgent sweating targets Taiyang; slow sweating targets Shaoyin, corresponding to organ meridians. Ma Huang Fu Zi Xi Xin Tang treats early Shaoyin fever with sinking pulse, interior harmony, and no sweat (steeping method). Ma Huang Tang treats Taiyang headache, stiff neck, floating pulse, no sweat, and interior harmony (releasing skin method). *Classic* states: "Treat the principal slowly, the guest urgently."

If Liver pulse is detected: exterior signs include bluish complexion, anger, string-like and floating pulses, aversion to cold, harmonious interior, normal urination/defecation. This indicates Gallbladder meridian involvement due to Liver governing wind. Add Qiang Huo (Notopterygium Root) and Fang Feng (Siler Root), 3 qian each, to Ma Huang Tang. If Heart pulse is detected: exterior signs include red face, dry mouth, laughter, floating and surging pulses, aversion to cold, harmonious interior. This indicates Small Intestine meridian involvement due to Heart governing heat. Add Huang Qin (Scutellaria Root) and Shi Gao (Gypsum), 3 qian each, to Ma Huang Tang. If Spleen pulse is detected: exterior signs include yellow face, belching, overthinking, taste preference, floating and moderate pulses, harmonious interior, aversion to cold. This indicates Stomach meridian involvement due to Spleen governing dampness. Add Bai Zhu (Atractylodes Rhizome) and Fang Feng, 3 qian each, to Ma Huang Tang. If Lung pulse is detected: exterior signs include pale face, sneezing, sorrow, weeping, floating and choppy pulses, harmonious interior, aversion to cold. This indicates Large Intestine meridian involvement due to Lung governing dryness. Add Gui Zhi (Cinnamon Twig) and Sheng Jiang (Fresh Ginger), 3 qian each, to Ma Huang Tang. If Kidney pulse is detected: exterior signs include dark face, fear, yawning, sinking pulses, harmonious interior, aversion to cold. This indicates Bladder meridian involvement due to Kidney governing cold. Add Fu Zi (Aconite Lateral Root) and Sheng Jiang, 3 qian each, to Ma Huang Tang.

These five conditions are "Exterior of Exterior," indicating pathogen in the skin, requiring urgent sweating, affecting Fu organs. "Exterior of Interior" requires slow purging. Signs include exterior manifestations, floating pulses, plus interior signs like fever, thirst, red urine, or bloody diarrhea. Pulses float but feel solid upon pressure, or pain exists. Remove Ma Huang and Xing Ren (Apricot Seed) from Ma Huang Tang, add organ-specific herbs, boil, divide into five doses. Start with 5 fen Da Huang (Rhubarb); increase by 1 qian if pathogens remain, then another 1.5 qian until cleared. This is "slow then urgent," for purging Exterior of Interior.

If Liver pulse shows interior signs: distension, dribbling, difficult defecation, tendon cramping, sinking and string-like pulses, harmonious interior, aversion to cold. Liver meridian disease. Add Qiang Huo and Fang Feng, 3 qian each, to Ma Huang Fu Zi Xi Xin Tang. If Heart pulse shows interior signs: vexation, heart pain, hot palms, hiccups, sinking and surging pulses, harmonious interior, aversion to cold. Heart meridian disease. Add Huang Qin and Shi Gao, 3 qian each, to the previous decoction. If Spleen pulse shows interior signs: abdominal fullness, indigestion, lethargy, sinking and moderate pulses, harmonious interior, aversion to cold. Lung meridian disease (Note: Text says Lung, likely error for Stomach/Spleen context, but translated as written). Add Bai Zhu and Fang Ji (Stephania Root), 3 qian each. If Lung pulse shows interior signs: cough, chills/fevers, sinking and choppy pulses, harmonious interior, aversion to cold. Lung meridian disease. Add Sheng Jiang and Gui Zhi, 3 qian each. If Kidney pulse shows interior signs: diarrhea, heaviness, cold legs, sinking pulses, harmonious interior, aversion to cold. Kidney meridian disease. Add Sheng Jiang and Fu Zi, 3 qian each.

These five conditions are "Interior of Exterior," requiring steaming/sweating, affecting Zang organs. "Interior of Interior" requires urgent purging. Signs include interior manifestations, sinking pulses, plus interior signs like red copious urine, constipation, bloody diarrhea, cough, inability to eat/drink, aversion to neither wind nor cold, fever, and thirst. Pulses sink and feel solid/painful upon pressure. This is Interior Excess, requiring rapid purging. Use Ma Huang Fu Zi Xi Xin Tang, remove Ma Huang, add organ-specific herbs, boil, divide into three doses. Start with 3 qian Da Huang; stop if pathogens clear. If not cleared, second dose adds 2 qian; third dose adds 1 qian. This is "urgent then slow," for purging Interior of Interior.