咳者，疫邪夹他邪干肺也。有初起在表，夹风邪干肺者，脉兼浮，咳多痰沫，必兼鼻鸣、自汗、洒淅恶寒，于
透表诸方中加前胡、桔梗、苏子、杏仁、淡豉。有夹水干肺者，不论表里，脉必兼缓，咳必多清痰，兼舌白、心
悸、胸满，或呕，或吞酸，于表里药中加桑皮、半夏、茯苓、川贝母、莱菔子。有疫热传里，燥火熏肺者，脉必
数，咳必无痰，有痰亦难出而咽痛，于里药中加花粉、黄芩、川贝、蒌仁。有病后阴伤肺燥者，脉必涩，咳必无
力，舌必赤而无苔，吴氏清燥养荣汤加麦冬、元参、知母、贝母。有屡经汗、下，或平素阴虚，肾气上逆者，
咳必兼上气，颧必时赤，足膝必清萎，脉必散，六味加枸杞、五味、牛膝。
疫邪兼咳者少，即有之，亦非大有关系之证，宜以病之表里大势为主，加治咳药于本方疗之。
渴乃热象，时疫为热证而有不渴者。盖初起湿热相兼，为蒸气，热未胜湿，则郁闷、心烦而不渴。热已大
盛，在经而不在胃，则烦躁、身热而不渴。在下而不在上，则燥结而不渴。在血分不在气分，则昏沉而不渴。疫邪初
从太阴发者，胸腹满、呕而不渴。此外，无有不渴者矣。
初起在表，发热、头痛、舌白而渴，脉必不浮、不沉而数，六神通解散加石膏、葛根，或九味羌活汤加石膏、
葛根。半表半里，口苦咽干，目胀而渴，脉必数，小柴胡汤加花粉、知母，或亦加石膏，或达原饮加石膏、葛根。
邪已入胃，作渴、身热、自汗，舌现黄苔，或酱色，或黑燥，当察其胸、胁、少腹，按之无痛处而渴者，为有热无
结，脉必洪，宜白虎汤。按之有痛处，为有热有结，痛在心下，脉必滑大，关上尤甚，小陷胸汤。在脐上及当脐，
关中脉必滑大，小承气汤。在脐下，尺中脉必滑大，调胃承气汤。心下至少腹俱痛，寸、关、尺必皆滑大，大承气
汤。痛在左胁不可按，左关脉必弦，或涩、或芤，桃仁承气汤。痛在右胁不可按，右关脉必弦，或滑、或迟、十枣
汤。渴而小便不利，少腹不可按，尺脉必数，四苓散、猪苓汤、六一散。汗、下后，身热已除而渴不止，余邪未尽
也，宜将前所用药再作小剂以利之。屡经汗、下，渴而舌上无苔，胸腹无满痛，心悸而烦，脉虚细，或浮散、或涩，
亡阴也，六味合生脉为主。
渴与烦躁同机，而渴轻于躁。渴有喜饮，而又有喜热饮、冷冻饮料之分。在他证不喜饮及喜热饮，则为真寒假
热。在时疫喜热饮，多发斑疹；不喜饮，热在血分。真寒假热，百不一见也。
时疫初起，以渴为机括，渴甚则热甚，渴微则热微。在末路，尤以渴为有余邪，不渴为无余邪也。
Cough is caused by the epidemic pathogen combining with other pathogens to invade the Lung. In some cases, at the onset, the pathogen is in the exterior and combines with Wind pathogen to invade the Lung; the pulse is accompanied by a Floating quality, coughing produces much frothy sputum, and it must be accompanied by nasal congestion (nasal whistling), spontaneous sweating, and aversion to cold with shivering. In such cases, add Qianhu (Peucedani Radix), Jiegeng (Platycodonis Radix), Suzi (Perillae Fructus), Xingren (Armeniacae Semen Amarum), and Danshi (Fermented Soybean) to various formulas for releasing the exterior. In cases where Water retention invades the Lung, regardless of whether the pathology is in the exterior or interior, the pulse must be accompanied by a Slow quality, coughing produces much clear phlegm, and it is accompanied by a white tongue coating, palpitations, chest fullness, vomiting, or acid regurgitation. In such cases, add Sangbai (Mori Cortex), Banxia (Pinelliae Rhizoma), Fuling (Poria), Chuanbeimu (Fritillariae Cirrhosae Bulbus), and Laifuzi (Raphani Fructus) to formulas addressing both exterior and interior. In cases where epidemic heat transmits to the interior and dry fire scorches the Lung, the pulse must be Rapid, coughing produces no sputum, and if there is sputum, it is difficult to expectorate accompanied by sore throat. In such cases, add Huafen (Trichosanthis Radix), Huangqin (Scutellariae Radix), Chuanbei (Fritillariae Cirrhosae Bulbus), and Louren (Trichosanthis Semen) to formulas treating the interior. In cases where Yin deficiency and Lung dryness occur after illness, the pulse must be Choppy, coughing lacks strength, and the tongue is red without coating. Use Wu's Qingzao Yangrong Tang (Clear Dryness and Nourish Ying Decoction) added with Maidong (Ophiopogonis Radix), Yuan Shen (Scrophulariae Radix), Zhimu (Anemarrhenae Rhizoma), and Beimu (Fritillariae Bulbus). In cases where repeated sweating or purging has occurred, or where there is constitutive Yin deficiency with rebellious Kidney Qi, coughing must be accompanied by upward rushing of Qi, the malar region becomes flushed intermittently, the feet and knees become cold and flaccid, and the pulse is Scattered. Use Liuwei Dihuang Wan (Six-Ingredient Pill with Rehmannia) added with Gouqi (Lycii Fructus), Wuweizi (Schisandrae Fructus), and Niuxi (Achyranthis Bidentatae Radix).
Epidemic pathogens combined with cough are rare; even when present, they are not critical syndromes. Treatment should focus on the general trend of exterior vs. interior pathology, adding herbs for cough to the primary formula.
Thirst is a sign of Heat. Although epidemic diseases are Heat syndromes, there are instances of no thirst. This is because at the onset, Dampness and Heat combine into vapor; if Heat does not overcome Dampness, the patient feels stifled and irritable but does not feel thirsty. If Heat is abundant but located in the meridians rather than the Stomach, the patient is restless and febrile but does not feel thirsty. If the pathology is lower rather than upper, causing dryness and accumulation, the patient does not feel thirsty. If the pathology is in the Blood level rather than the Qi level, the patient is lethargic and does not feel thirsty. If the epidemic pathogen originates from the Taiyin channel, presenting with chest and abdominal fullness and vomiting, the patient does not feel thirsty. Apart from these, there are no cases without thirst.
At the onset, if in the exterior with fever, headache, white tongue coating, and thirst, the pulse is neither Floating nor Deep but Rapid. Use Liushentongjie San (Six-Way Unblocking Powder) added with Shigao (Gypsum Fibrosum) and Gegen (Puerariae Lobatae Radix), or Jiuwei Qianghuo Tang (Nine-Herb Notopterygium Decoction) added with Shigao and Gegen. At the half-exterior half-interior stage, with bitter taste, dry throat, distended eyes, and thirst, the pulse is Rapid. Use Xiaochaihu Tang (Minor Bupleurum Decoction) added with Huafen and Zhimu, or also with Shigao, or Dayuan Yin (Origin-Reaching Drink) added with Shigao and Gegen. If the pathogen has entered the Stomach, causing thirst, fever, and spontaneous sweating, with a yellow, pasty, or black-dry tongue coating, examine the chest, hypochondrium, and lower abdomen. If pressing reveals no pain and thirst persists, it indicates Heat without accumulation; the pulse is Surging, and Baihu Tang (White Tiger Decoction) is appropriate. If pressing reveals pain, it indicates Heat with accumulation. If pain is in the epigastrium, the pulse is Slippery and Large, especially at the Guan position; use Xiaoxiantong Tang (Minor Trap-Lifting Decoction). If pain is above or at the umbilicus, the Guan and Cun pulses are Slippery and Large; use Xiao Chengqi Tang (Minor Order-the-Qi Decoction). If pain is below the umbilicus, the Chi pulse is Slippery and Large; use Tiaowei Chengqi Tang (Regulate-the-Stomach Order-the-Qi Decoction). If pain extends from the epigastrium to the lower abdomen, all three pulses (Cun, Guan, Chi) are Slippery and Large; use Da Chengqi Tang (Major Order-the-Qi Decoction). If pain is in the left hypochondrium and cannot be pressed, the Left Guan pulse is Wiry, or Choppy, or Hollow; use Tao Ren Chengqi Tang (Peach Kernel Order-the-Qi Decoction). If pain is in the right hypochondrium and cannot be pressed, the Right Guan pulse is Wiry, or Slippery, or Slow; use Shizao Tang (Ten-Jujube Decoction). If thirst is accompanied by difficulty in urination and tenderness in the lower abdomen, the Chi pulse is Rapid; use Siling San (Four-Poria Powder), Zhuling Tang (Polyporus Decoction), or Liuyi San (Six-to-One Powder). After sweating or purging, if fever subsides but thirst persists, residual pathogen remains; administer previous formulas in small doses to drain it. After repeated sweating and purging, if thirst occurs with a tongue lacking coating, no chest/abdominal fullness or pain, palpitations, irritability, and a Deficient-Fine, or Floating-Scattered, or Choppy pulse, this indicates exhaustion of Yin. Use Liuwei Dihuang Wan (Six-Ingredient Pill with Rehmannia) combined with Shengmai San (Generate the Pulse Powder) as the main treatment.
Thirst and restlessness often occur together, but thirst is milder than restlessness. Thirst may involve a desire to drink, distinguishing between preference for hot drinks and cold drinks. In other syndromes, aversion to drinking or preference for hot drinks indicates True Cold and False Heat. In epidemic diseases, preference for hot drinks suggests impending macules and papules; aversion to drinking indicates Heat in the Blood level. True Cold and False Heat is extremely rare.
In the early stages of epidemic diseases, thirst serves as a key indicator: severe thirst indicates severe Heat, while mild thirst indicates mild Heat. In the late stages, thirst indicates residual pathogen, while absence of thirst indicates no residual pathogen.