风寒暑湿。四气为病。加燥火而六焉。则不得概以伤寒混治也。盖寒伤经
络。足太阳经主之。风伤皮毛。手太阴经主之。而寒亦有伤肺风亦能犯太
阳。总之以辛温者治寒。辛凉者治风。其大较也。然麻黄虽热。体轻反能入
肺。故有三拗汤以泻肺邪。桂枝辛甘。性热反可祛寒。故入麻黄汤以调营
卫。然世俗相沿。每用桂枝治风。不若以荆防为当。盖肺属金畏热。尝见投
桂枝者。往往口鼻见红。及咽痛等候也。抑寒伤形。暑伤气。伤形者。邪有余。
则宜散。伤气者。正不足。则宜补。故均有发热。而自汗气喘。体倦虚烦。及面
垢前板齿燥泄泻。种种不同。若兼感寒。则无是证矣。宜以十味香薷。清暑
益气大顺散。分别以治。岂得混于寒哉。寒伤经络。身热而痛。湿伤筋骨。身
重而痛。但湿流肢节或腰脚。脉必细或缓。兼寒则拘挛。兼热则肿赤。甚为
呕逆。为烦满。宜以羌活胜湿汤。苍术平胃散分内外治之。则又与寒迥别
也。至于燥火二症。且甚悬绝者乎。
按寒与风异治者。盖寒无汗而风有汗也。寒与暑异治者。寒欲发汗。而
暑欲止汗也。寒与湿异治者。寒从汗解而湿不可大汗也。寒与燥火异
治者。燥宜润。得风药而愈烈。火宜降。得风药而弥炽也。
荆防汤 治伤风咳嗽
防风 荆芥 前胡 桔梗 广皮 枳壳（各一钱） 甘草（三分）
生姜一片。水煎。
三拗汤 治肺风。痰喘初起无汗者。
麻黄（不去节） 杏仁（不去尖） 甘草（不炙各等分）
生姜水煎。
参苏饮 治肺寒咳嗽。
人参 紫苏 前胡 桔梗 陈皮 枳壳 葛根 半夏 茯苓 甘草（各等分） 木香（磨入一分）
枣一枚。姜一片。水煎。
香薷饮 治一切暑毒。霍乱吐泻。
香薷（三钱） 茯苓 白扁豆（炒） 浓朴（姜制） 甘草（各一钱）
水煎服。加黄连名黄连香薷饮。
十味香薷散 治伏暑。身体倦怠。神昏头重。吐泻等症。
香藿（一两） 人参 陈皮 白术（土炒） 茯苓
甘草（炙） 木瓜 浓朴（姜制） 扁豆（炒） 黄 （各半两炙）
每服一两。水煎冷服。
大顺散 治纳凉太过。饮冷太多。脾胃受寒。霍乱吐泻。水谷不入。脏腑不
调。此舍时从症之剂也。
甘草（二两） 干姜 杏仁（去皮尖） 肉桂（去皮各四两）
上先将甘草炙熟。次入干姜同炒令姜裂。又入杏仁同炒令杏仁不作
声为度。后入肉桂为末。每服二钱。井花水调下。沸汤点服亦得。
清暑益气汤
苍术（钱半米泔浸炒） 黄 （蜜炙） 升麻（各一钱） 人参 白术（土炒）
当归 陈皮 神曲（炒） 泽泻（各五分） 干葛 青皮 甘草（炙） 黄柏 麦冬（各三
分） 五味子（九粒杵）
水煎服。
羌活胜湿汤
羌活 独活 本 川芎 防风（各一钱） 甘草 蔓荆子（各三分）
水煎。
平胃散
茅术（米泔浸炒） 浓朴（姜汁炒） 陈皮（各一钱） 甘草（三分炙）
水煎。
风寒暑湿，这四种气候因素致病。再加上燥和火，就构成了六种邪气。因此，不能一概用治疗伤寒的方法来混淆处理。
大抵而言，寒邪损伤经络，由足太阳经主管；风邪损伤皮毛，由手太阴经主管。然而，寒邪也有伤肺的时候，风邪也能侵犯太阳经。总体原则是：用辛温的药物来治疗寒邪，用辛凉的药物来治疗风邪，这是大概的规律。
但是，麻黄虽然性热，但质地轻清，反而能入肺经，所以有三拗汤用来泻除肺中的邪气。桂枝味辛甘，性热，反而可以祛除寒邪，所以加入麻黄汤中以调和营卫。然而世俗沿袭旧习，常用桂枝治疗风邪，这不如使用荆芥、防风恰当。因为肺属金，畏惧热邪，我常看到投用桂枝后，患者往往出现口鼻出血，以及咽喉疼痛等症状。
再者，寒邪损伤形体，暑邪损伤气机。损伤形体的，邪气有余，适宜发散；损伤气机的，正气不足，适宜补益。所以，虽然都有发热的症状，但自汗、气喘、身体疲倦、心中虚烦，以及面色垢浊、前板齿干燥、泄泻等表现各不相同。如果兼感寒邪，就不会有这些症状了。适宜分别使用十味香薷散、清暑益气汤、大顺散来治疗，怎么能将它们混同于寒证呢？
寒邪损伤经络，表现为身体发热且疼痛；湿邪损伤筋骨，表现为身体沉重且疼痛。只是湿气流注于四肢关节或腰脚时，脉象必定细弱或缓怠。兼夹寒邪则出现拘挛，兼夹热邪则出现红肿赤痛，严重时会呕吐逆气，感到烦闷胀满。适宜以羌活胜湿汤、苍术平胃散分别内外进行治疗，这就又与寒证截然不同了。至于燥和火两种病症，更是相差甚远。
按语：寒与风之所以异治，是因为寒证无汗而风证有汗。寒与暑之所以异治，是因为寒证欲通过发汗解表，而暑证欲止汗。寒与湿之所以异治，是因为寒证从汗而解，而湿证不可大汗。寒与燥火之所以异治，是因为燥证宜润，若用风药则病情加剧；火证宜降，若用风药则火势更旺。
荆防汤：治疗伤风咳嗽。
防风、荆芥、前胡、桔梗、广皮（陈皮）、枳壳（各一钱），甘草（三分）。生姜一片。水煎服。
三拗汤：治疗肺风，痰喘初起且无汗者。
麻黄（不去节）、杏仁（不去尖）、甘草（不炙，各等分）。生姜水煎服。
参苏饮：治疗肺寒咳嗽。
人参、紫苏、前胡、桔梗、陈皮、枳壳、葛根、半夏、茯苓、甘草（各等分），木香（磨汁调入一分）。大枣一枚，生姜一片。水煎服。
香薷饮：治疗一切暑毒，霍乱吐泻。
香薷（三钱），茯苓、白扁豆（炒）、浓朴（姜制）、甘草（各一钱）。水煎服。加黄连名为黄连香薷饮。
十味香薷散：治疗伏暑，身体倦怠，神志昏蒙，头重，吐泻等症状。
藿香（一两），人参、陈皮、白术（土炒）、茯苓、甘草（炙）、木瓜、浓朴（姜制）、扁豆（炒）、黄芪（各半两，炙）。每服一两，水煎冷服。
大顺散：治疗纳凉太过，饮冷太多，导致脾胃受寒，霍乱吐泻，水谷不入，脏腑不调。这是舍时从症的方剂。
甘草（二两），干姜、杏仁（去皮尖）、肉桂（去皮，各四两）。先将甘草炙熟，次入干姜同炒至姜裂，又入杏仁同炒至杏仁不再发出响声为度，后入肉桂研为末。每服二钱，井花水调下，沸汤点服也可以。
清暑益气汤：
苍术（钱半，米泔浸炒），黄芪（蜜炙），升麻（各一钱），人参、白术（土炒）、当归、陈皮、神曲（炒）、泽泻（各五分），干葛、青皮、甘草（炙）、黄柏、麦冬（各三分），五味子（九粒，捣碎）。水煎服。
Wind, cold, summerheat, and dampness are four pathogenic factors causing disease. Adding dryness and fire makes six; thus, they cannot be indiscriminately treated as Cold Damage (Shanghan). Generally speaking, cold damages the meridians, governed by the Foot-Taiyang Meridian; wind damages the skin and hair, governed by the Hand-Taiyin Meridian. However, cold can also damage the Lungs, and wind can invade the Taiyang. The general principle is to treat cold with acrid-warm herbs and wind with acrid-cool herbs.
Although Ephedrae Herba (Mahuang) is hot in nature, its texture is light, allowing it to enter the Lung meridian; therefore, San'ao Decoction (Three Unrestrained Decoction) is used to drain pathogenic factors from the lungs. Cinnamon Twig (Guizhi) is acrid and sweet, hot in nature, yet capable of dispelling cold; thus, it is included in Mahuang Decoction to harmonize Ying (Nutritive) and Wei (Defensive) Qi. However, common practice often uses Guizhi for wind, which is less appropriate than using Schizonepetae Spica (Jingjie) and Saposhnikoviae Radix (Fangfeng). Since the Lung belongs to Metal and fears heat, I have often seen patients develop bleeding from the mouth and nose, as well as sore throat, after taking Guizhi.
Furthermore, cold damages the form (body structure), while summerheat damages Qi. When the form is damaged, there is an excess of pathogenic factors, requiring dispersal; when Qi is damaged, there is a deficiency of healthy Qi, requiring tonification. Therefore, although fever may be present in both, symptoms such as spontaneous sweating, panting, physical fatigue, mental restlessness, greasy complexion, dryness of the anterior teeth, and diarrhea differ significantly. If accompanied by cold invasion, these specific symptoms would not appear. One should use Shiwei Xiangru Powder (Ten-Ingredient Elsholtzia Powder), Qingshu Yiqi Decoction (Clear Summerheat and Tonify Qi Decoction), or Dashun Powder respectively, rather than confusing them with cold patterns.
Cold damaging the meridians presents with fever and pain; dampness damaging the sinews and bones presents with heaviness and pain. When dampness flows into the limbs and joints or waist and feet, the pulse must be fine or slow. Accompanied by cold, there is spasmodic contraction; accompanied by heat, there is swelling and redness. Severe cases involve vomiting, retching, vexation, and fullness. These should be treated internally and externally with Qianghuo Shengshi Decoction (Notopterygium Decoction to Overcome Dampness) or Cangzhu Pingwei Powder (Atractylodes Decoction to Calm the Stomach), which is distinctly different from cold. As for dryness and fire, their differences are even more extreme.
Note: Cold and wind are treated differently because cold patterns lack sweating, whereas wind patterns have sweating. Cold and summerheat are treated differently because cold requires inducing sweating, whereas summerheat requires stopping sweating. Cold and dampness are treated differently because cold resolves through sweating, whereas dampness should not be resolved through heavy sweating. Cold and dryness/fire are treated differently because dryness requires moistening (wind herbs exacerbate it), and fire requires descending (wind herbs intensify it).
Jingfang Decoction: Treats wind-cold injury with cough.
Saposhnikoviae Radix (Fangfeng), Schizonepetae Spica (Jingjie), Peucedani Radix (Qianhu), Platycodonis Radix (Jiegeng), Citri Reticulatae Pericarpium (Guangpi), Aurantii Fructus (Zhike) (each 1 qian), Licorice Root (Gancao) (0.3 qian). One slice of fresh ginger. Decoct in water and take.
San'ao Decoction: Treats lung wind, initial stage of phlegm-panting without sweating.
Ephedrae Herba (Mahuang) (not removing joints), Prunus Armeniacae Semen Amarum (Xingren) (not removing tips), Glycyrrhizae Radix et Rhizoma (Gancao) (not roasted, equal parts). Decoct with ginger water and take.
Shenxu Yin: Treats lung cold with cough.
Ginseng Radix (Renshen), Perillae Folium (Zisu), Peucedani Radix (Qianhu), Platycodonis Radix (Jiegeng), Citri Reticulatae Pericarpium (Chenpi), Aurantii Fructus (Zhike), Puerariae Radix (Gegen), Pinelliae Rhizoma Preparatum (Banxia), Poria (Fuling), Glycyrrhizae Radix et Rhizoma (Gancao) (equal parts), Aucklandiae Radix (Muxiang) (ground, add 0.1 qian). One jujube, one slice of ginger. Decoct in water and take.
Xiangru Yin: Treats all types of summerheat toxicity, cholera-like disorder with vomiting and diarrhea.
Elsholtziae Herba (Xiangru) (3 qian), Poria (Fuling), Phaseoli Semen Album (Bai Biandou) (stir-fried), Magnoliae Officinalis Cortex (Nongpu) (processed with ginger juice), Glycyrrhizae Radix et Rhizoma (Gancao) (each 1 qian). Decoct in water and take. Adding Scutellariae Radix (Huanglian) makes it Huanglian Xiangru Yin.
Shiwei Xiangru San: Treats latent summerheat, physical fatigue, mental confusion, heavy head, vomiting, and diarrhea.
Agastaches Herba (Huoxiang) (1 liang), Ginseng Radix (Renshen), Citri Reticulatae Pericarpium (Chenpi), Atractylodis Rhizoma (Baizhu) (soil-roasted), Poria (Fuling), Glycyrrhizae Radix et Rhizoma (Gancao) (roasted), Chaenomelis Fructus (Mu Gua), Magnoliae Officinalis Cortex (Nongpu) (processed with ginger juice), Phaseoli Semen Album (Biandou) (stir-fried), Astragali Radix (Huangqi) (each 0.5 liang, roasted). Take 1 liang per dose, decoct in water and take cold.
Dashun Powder: Treats excessive exposure to coolness and excessive consumption of cold drinks, leading to stomach-spleen cold injury, cholera-like disorder with vomiting and diarrhea, inability to retain food/water, and internal organ dysfunction. This is a formula that prioritizes symptoms over seasonal timing.
Glycyrrhizae Radix et Rhizoma (Gancao) (2 liang), Zingiberis Rhizoma (Ganjiang), Prunus Armeniacae Semen Amarum (Xingren) (skin and tip removed), Cinnamomi Cortex (Rougui) (skin removed, each 4 liang). First, roast Gancao until cooked. Then add Ganjiang and stir-fry until Ganjiang cracks. Add Xingren and stir-fry until no longer sizzling. Finally, add Rougui and grind into powder. Take 2 qian per dose, mixed well water (Jinghua Shui), or prepared with boiling water.
Qingshu Yiqi Decoction:
Atractylodis Rhizoma (Cangzhu) (1.5 qian, soaked in rice wash water and stir-fried), Astragali Radix (Huangqi) (honey-roasted), Cimicifugae Rhizoma (Shengma) (each 1 qian), Ginseng Radix (Renshen), Atractylodis Rhizoma (Baizhu) (soil-roasted), Angelicae Sinensis Radix (Danggui), Citri Reticulatae Pericarpium (Chenpi), Massa Medicata Fermentata (Shenqu) (stir-fried), Alismatis Rhizoma (Zexie) (each 0.5 fen), Puerariae Radix (Gange), Citri Reticulatae Pericarpium Viride (Qingpi), Glycyrrhizae Radix et Rhizoma (Gancao) (roasted), Phellodendri Cortex (Huangbai), Ophiopogonis Tuber (Maidong) (each 0.3 fen), Schisandrae Fructus (Wuweizi) (9 grains, crushed). Decoct in water and take.
Qianghuo Shengshi Decoction:
Notopterygii Rhizoma et Radix (Qianghuo), Angelicae Dahuricae Radix (Duohuo), Ligustici Rhizoma et Radix (Ben), Chuanxiong Rhizoma (Chuanxiong), Saposhnikoviae Radix (Fangfeng) (each 1 qian), Glycyrrhizae Radix et Rhizoma (Gancao), Viticis Fructus (Manjingzi) (each 0.3 fen). Decoct in water and take.
Pingwei Powder:
Atractylodis Rhizoma (Maocangzhu) (soaked in rice wash water and stir-fried), Magnoliae Officinalis Cortex (Nongpu) (stir-fried with ginger juice), Citri Reticulatae Pericarpium (Chenpi) (each 1 qian), Glycyrrhizae Radix et Rhizoma (Gancao) (0.3 fen, roasted). Decoct in water and take.