某 风伤卫阳，咳，频嚏多涕，怯风，头目重眩，宜辛以散之。用防风、苏叶、杏仁、川芎、桔梗、
甘菊、姜，微汗而愈。
某 冬春喜浴，腠疏感风。以玉屏风散固之。
某 风温伤肺，咳而眩。用轻凉肃上，丹皮、杏仁、桑叶、山栀、贝母，枇杷叶。再服效。
自霜降后，天冷冱寒，感之即病者，伤寒也。脉浮紧为伤寒，脉浮缓为伤风，感寒不即病者，春为温，夏
为热。一日太阳受之，尺寸俱浮，以其脉上连风府，故头项痛，腰脊强。二日阳明受之，尺寸俱长，以其脉挟
鼻络于目，故身热目痛，鼻干，不得卧。三日少阳受之，尺寸俱弦，以其脉循胁，络于耳，故胁痛而耳聋。
此三阳受病，未入腑，可汗而已。若不解，四日太阴受之，尺寸俱沉细，以其脉布胃中络于嗌，故腹满而嗌干。
五日少阴受之，尺寸俱沉，以其脉络于肺系舌本，故口燥舌干而渴。六日厥阴受之，尺寸俱微缓，以其脉循
阴器络于肝，故烦满而囊缩。此三阴受病，已入腑，可下而已。三阴经有汗下温三法，不但可下而已
也。腑谓胃腑。其两感于寒者，一日太阳与少阴俱病，有头痛项强，而又口干烦渴也。二日阳明与太阴俱病，
有身热谵语，而又腹满不欲食也。三日少阳与厥阴俱病，有胁痛耳聋，而又囊缩厥逆也。此阴阳表里俱病，
欲汗之则有里症，欲下之则有表症，故《内经》、仲景皆云必死。洁古大羌活汤主之。伤寒有传经，有直
中。传经者，由太阳传阳明，由阳明传少阳，由少阳传太阴，由太阴传少阴，由少阴传厥阴，此为循经传。
太阳传少阳，为越经传。太阳传太阴，为误下传。太阳传少阴，为表里传。太阳传厥阴，为首尾传。太阳传本
腑膀胱，为传本。阳明有不传少阳而径入本腑者，胃腑。少阳有不传三阴而径入胃腑者。有传一二经而止者，
有始终止在一经者，当随症施治，不必拘日数。其直中者，则不出阳经传入而径中三阴者也。夫传经之邪，
在表为寒，入里则化热，不比直中之邪，但寒无热，为急宜温也。先明传经直中，庶寒热之剂，不致混投。
而表里寒热，尤所宜辨。太阳为表之表，阳明为表之里，少阳居表里之间，为半表半里，太阴、少阴、厥阴
俱为里。凡伤寒自阳经传入阴经者，为热邪，不由阳经传入而直入阴经者，谓之中寒，则为寒邪。钟龄程氏
条而析之，附录于此。
伤寒症，有表寒，有里寒，有表热，有里热，有表里皆热，有表里皆寒，有表寒里热，有表热里寒。
何谓表寒，伤寒初客太阳，头痛发热而恶寒者，名曰外感，经所谓体若燔炭，汗出而散是也。阳明解肌，
少阳和解，其理一也，何谓里寒，凡伤寒不由阳经传入，而直入阴经者，手足厥冷，脉微细，下利清谷，名曰
中寒，仲景所谓急温之，宜四逆汤是也。何谓表热，凡伤于寒，则为病热，表邪壅遏，不得外泄，或荣弱
卫强，自汗不解，宜桂芍和荣，柴葛解肌是也。何谓里热，凡伤寒渐次传里，与春温夏热症，热邪内发，皆
为里热。其在太阴则津液少，少阴则咽干口燥，厥阴则消渴。仲景所谓急下之，而用大柴胡、三承气者是也。
何谓表里皆热，如伤寒阳明症，传于本腑，外而肌肉，内而胃腑，热气熏蒸，口渴谵语，此散漫之热邪未
结聚，治用白虎汤，外透肌肤，内清腑脏，俾表里两解，不比邪热结实，专在肠胃，可下而愈也。正伤寒有此，
温热症更多有此。何谓表里皆寒，凡伤寒
表受寒邪，更兼直中于里，此为两感寒症，仲景用麻黄附子细辛汤是也。何谓表寒里热，如两感热症，一日太
阳与少阴同病，二日阳明与太阴同病，三日少阳与厥阴同病，三阳为寒，三阴已成热症，岂非表寒而里热乎。
亦有火郁在内，更加外感于寒，亦为表寒里热之候，又有火亢已极，反兼水化，内热闭结而外有恶寒之状者，
表似寒而里实热，误投热剂，下咽即败矣。何谓表热里寒，如人本体虚寒，而外感温热之邪，此为标热本寒，
清剂不宜太过，更有阴寒在下，逼其无根失守之火，发扬于上，肌肤大热，欲坐卧泥水中，表似热而里实寒，
误投寒剂，入胃即危矣。伤寒变症不一，总不外表里寒热，其表里寒热之变，总不外此八言，以为纲领。
A patient suffered from wind pathogen damaging the Wei Yang (Defensive Yang), presenting with cough, frequent sneezing with abundant nasal discharge, aversion to wind, and a heavy, dizzy sensation in the head and eyes. It is appropriate to use acrid methods to disperse the pathogen. Fangfeng (Saposhnikovia Root), Ziye (Perilla Leaf), Xingren (Apricot Seed), Chuanxiong (Ligusticum Rhizome), Jiegeng (Platycodon Root), Ganju (Chrysanthemum Flower), and Shengjiang (Fresh Ginger) were used; mild sweating led to recovery.
Another patient, who enjoyed bathing during winter and spring, had loose interstices (pores) and contracted wind. Yupingfeng San (Jade Windscreen Powder) was used to consolidate the exterior.
Yet another patient suffered from wind-warmth injuring the Lung, presenting with cough and dizziness. Light, cool, and descending methods were employed using Mudanpi (Tree Peony Bark), Xingren (Apricot Seed), Sangye (Mulberry Leaf), Shanzhi (Gardenia Fruit), Beimu (Fritillaria Bulb), and Pipaye (Loquat Leaf); improvement occurred after further doses.
After the Frost Descent solar term, when the weather turns cold and freezing, illness contracting immediately upon exposure to cold is termed Shanghan (Cold Damage). A floating and tight pulse indicates Shanghan, while a floating and slow pulse indicates Shangfeng (Wind Strike). If cold contracts but does not cause immediate illness, it develops into Wenbing (Warm Disease) in spring and Rebing (Heat Disease) in summer. On the first day, the Taiyang (Greater Yang) channel is affected; the cun and chi pulses are both floating because its meridian connects upward to the Fengfu point (GV16), causing headache, neck stiffness, and lower back/spine rigidity. On the second day, the Yangming (Yang Brightness) channel is affected; the cun and chi pulses are both long because its meridian flanks the nose and connects to the eyes, causing fever, eye pain, dry nose, and inability to lie down. On the third day, the Shaoyang (Lesser Yang) channel is affected; the cun and chi pulses are both wiry because its meridian follows the hypochondrium and connects to the ears, causing hypochondriac pain and deafness. When these three Yang channels are diseased and the pathogen has not entered the Fu organs, it can be cured by sweating. If unresolved, on the fourth day, the Taiyin (Greater Yin) channel is affected; the cun and chi pulses are both deep and fine because its meridian spreads in the stomach and connects to the throat, causing abdominal fullness and dry throat. On the fifth day, the Shaoyin (Lesser Yin) channel is affected; the cun and chi pulses are both deep because its meridian connects to the lung system and tongue root, causing dry mouth, dry tongue, and thirst. On the sixth day, the Jueyin (Terminal Yin) channel is affected; the cun and chi pulses are both faint and slow because its meridian follows the genitalia and connects to the liver, causing irritability, fullness, and retraction of the scrotum. When these three Yin channels are diseased, the pathogen has entered the Fu organs, and it can be cured by purging. The three Yin channels have sweating, purging, and warming methods, not just purging alone. Here, "Fu" refers to the Stomach Fu organ. In cases of Lianggan (Double Exposure to Cold), where Yin and Yang channels are simultaneously affected: on the first day, Taiyang and Shaoyin are both diseased, presenting with headache, neck stiffness, yet also dry mouth and irritability/thirst; on the second day, Yangming and Taiyin are both diseased, presenting with fever and delirium, yet also abdominal fullness and loss of appetite; on the third day, Shaoyang and Jueyin are both diseased, presenting with hypochondriac pain and deafness, yet also scrotal retraction and cold limbs. This is simultaneous disease of Yin/Yang and interior/exterior. Sweating is contraindicated due to interior signs, and purging is contraindicated due to exterior signs; thus, both the *Neijing* and Zhang Zhongjing state this is fatal. Jiegu's Da Qianghuo Tang (Great Notopterygium Decoction) is indicated. Shanghan involves transmission along meridians (Chuanjing) or direct invasion (Zhizhong). Transmission involves progression from Taiyang to Yangming, Yangming to Shaoyang, Shaoyang to Taiyin, Taiyin to Shaoyin, and Shaoyin to Jueyin, known as Xunjing Chuan (Sequential Transmission). Taiyang transmitting to Shaoyang is Yuejing Chuan (Skipping Channel Transmission). Taiyang transmitting to Taiyin is Wuxia Chuan (Transmission due to Misguided Purging). Taiyang transmitting to Shaoyin is BiaoLi Chuan (Exterior-Interior Transmission). Taiyang transmitting to Jueyin is Shouwei Chuan (Head-Tail Transmission). Taiyang transmitting to its own Fu organ (Bladder) is Chuanben (Transmission to Original Organ). Yangming may transmit directly to its Fu organ (Stomach) without passing through Shaoyang. Shaoyang may transmit directly to the Stomach Fu without passing through the three Yin channels. Some transmissions stop after one or two channels; some remain confined to one channel throughout. Treatment should follow symptoms, not rigidly adhere to days. Direct invasion (Zhizhong) bypasses Yang channels and strikes the three Yin channels directly. Pathogens transmitted along meridians are cold at the exterior but transform into heat upon entering the interior, unlike direct invasion pathogens which present only with cold and no heat, requiring urgent warming. Clarifying transmission versus direct invasion prevents indiscriminate use of cold/hot agents. Differentiating exterior/interior and cold/heat is crucial. Taiyang is exterior-exterior; Yangming is exterior-interior; Shaoyang is between exterior and interior, i.e., half-exterior half-interior; Taiyin, Shaoyin, and Jueyin are all interior. Shanghan transmitting from Yang to Yin channels constitutes Heat Pathogen; direct entry into Yin channels without passing through Yang is called Zhonghan (Direct Cold Strike), constituting Cold Pathogen. Zhong Ling Cheng Shi analyzed this in detail and appended it here.
Shanghan symptoms include Exterior Cold, Interior Cold, Exterior Heat, Interior Heat, Simultaneous Exterior-Interior Heat, Simultaneous Exterior-Interior Cold, Exterior Cold with Interior Heat, and Exterior Heat with Interior Cold. What is Exterior Cold? When Shanghan initially affects Taiyang, causing headache, fever, and aversion to cold, it is named Waigan (External Contraction). The classics describe it as body heat like burning charcoal, resolved by sweating. Yangming resolves muscle layer, Shaoyang harmonizes, following similar principles. What is Interior Cold? When Shanghan does not transmit via Yang channels but directly enters Yin channels, presenting with cold extremities, faint/fine pulse, and diarrhea with undigested food, it is named Zhonghan (Direct Cold Strike). Zhang Zhongjing states urgent warming is needed, using Sini Tang (Recovery Decoction). What is Exterior Heat? Injury by cold transforms into heat disease. Exterior pathogen obstruction prevents external release, or Ying deficiency with Wei excess causes spontaneous sweating unrelieved. Guizhi Tang (Cinnamon Twig Decoction) harmonizes Ying and Wei; Chaihu Ge Gen Tang (Bupleurum and Kudzu Decoction) resolves the muscle layer. What is Interior Heat? Shanghan gradually transmits inward, resembling Spring Warmth and Summer Heat syndromes, where heat pathogen originates internally. In Taiyin, fluids are scant; in Shaoyin, throat is dry and mouth parched; in Jueyin, there is excessive thirst. Zhang Zhongjing states urgent purging is needed, using Daxiehu Tang (Major Bupleurum Decoction) or the Three Chengqi Decoctions. What is Simultaneous Exterior-Interior Heat? As in Yangming Shanghan transmitting to its Fu organ, heat steams externally to muscles and internally to the stomach, causing thirst and delirium. This is diffuse heat pathogen not yet condensed. Baibao Tang (White Tiger Decoction) is used to vent heat from skin and clear Fu organs, resolving both exterior and interior. This differs from condensed heat pathogen fixed in intestines/stomach, curable by purging. Zheng Shanghan (True Cold Damage) has this; Wenre Bing (Warm-Heat Diseases) have it even more. What is Simultaneous Exterior-Interior Cold? When Shanghan exterior receives cold pathogen and concurrently suffers direct invasion to interior, it is Lianggan Hanzheng (Double Exposure Cold Syndrome). Zhang Zhongjing uses Mahuang Fuzi Xixin Tang (Ephedra, Aconite, and Asarum Decoction). What is Exterior Cold with Interior Heat? Like Lianggan Rezheng (Double Exposure Heat Syndrome): Day 1 Taiyang/Shaoyin, Day 2 Yangming/Taiyin, Day 3 Shaoyang/Jueyin. Three Yang are cold, Three Yin have become heat syndromes—is this not Exterior Cold with Interior Heat? Also, Fire stagnation internally plus external cold contraction presents as Exterior Cold/Interior Heat. Or extreme Fire hyperactivity mimicking Water transformation, with internal heat closure and external aversion to cold: Exterior appears cold but Interior is truly hot. Misusing hot agents leads to failure upon ingestion. What is Exterior Heat with Interior Cold? Individuals with inherent deficiency-cold contracting warm-heat pathogens present as Biao Re Ben Han (Surface Heat, Root Cold). Cooling agents should not be excessive. Also, Yin-cold below forces rootless, unstable fire to flare upward, causing great skin heat and desire to sit/lie in mud/water: Exterior appears hot but Interior is truly cold. Misusing cold agents leads to danger upon reaching the stomach. Shanghan variable syndromes vary but ultimately do not exceed Exterior/Interior Cold/Heat. These variations are summarized in eight terms as the guideline.