【歌】恶寒由是六阳虚，振栗憎寒火有余。外感脉浮头项痛，肺虚洒淅更何疑。
【论】夫恶寒，有阳虚腠理疏泄，不任风寒，必自汗多也。有火盛甚，反兼水化制之，故振栗恶寒也。有
外感风寒
之邪，则有表证，脉浮，头痛，发热。有肺受火克，虚而失所司，则洒淅恶寒也。有表气虚不能固腠理，或汗
多故也。仲景云∶发热恶寒，发于阳也；无热恶寒，发于阴也。此阴阳虚实之理，判然明矣。
表虚
表虚必自汗多，恶寒者，桂枝汤。汗多，表虚不能护卫，脉弱恶风寒，黄 建中汤。
桂枝汤
桂枝（上） 芍药（中） 甘草（下）
上，生姜三片，大枣二枚，水二盏，煎至一盏，稍温服。
小建中汤
即桂枝汤加饴糖一合。
黄 建中汤
即小建中汤加黄 等分。
阳虚
阳虚不任风寒，体弱脉虚而恶寒者，四君子汤倍加黄 、桂枝。虚甚者，再加熟附子二、三片，或黄
建中汤加附子。
四君子汤（方见脾胃条。）
火盛
火盛甚者，反恶寒，非寒也，乃亢极反兼水化。制之，四物汤加黄 、黄柏、黄连，火降寒自已。
四物汤（方见血证条。）
卫不和
气为卫，主卫护皮毛，温分肉，实腠理。卫不和，则腠理不固而恶寒者，调中益气汤倍加黄 、桂枝。
调中益气汤（方见气证条。）
外感
外感风寒，无汗，发热恶寒，麻黄汤。有汗，恶风，桂枝汤。平时感寒邪，恶寒发热者，香苏散。
麻黄汤（方见发热条。）
香苏散
香附（上） 苏叶（上） 陈皮（中） 甘草（下）
上锉，一剂，生姜三片，枣二枚，水二盏，煎八分，热服。
加川芎、白芷，名芎芷香苏散。
肺病
肺受火邪而失所司，不能固腠理，洒淅恶寒者，甘桔汤加酒黄芩、山栀、麦门冬、五味子、酸枣仁。
甘桔汤
甘草 桔梗（等分）
上，用水煎服。
【歌诀】恶寒症状源于六经阳气虚弱，若出现战栗、畏寒且体内火邪有余，则属此类。外感风寒时脉象浮起并伴有头项疼痛；若是肺气虚弱导致的洒淅恶寒，更无需怀疑。
【论述】所谓恶寒，有的是因为阳气虚弱导致腠理（皮肤毛孔及其附属组织）疏松泄气，无法抵御风寒，必然伴随自汗多出的症状。有的是因为火邪极盛，反而兼有水化之象来制约它，所以出现战栗和恶寒。有的是因为外感风寒之邪，从而出现表证，表现为脉浮、头痛、发热。有的是因为肺受火邪克制，肺气虚弱而失去其正常职能，从而出现洒淅恶寒的症状。有的是因为表气虚弱不能固护腠理，或者是汗出过多所致。张仲景说：“发热伴恶寒，是发于阳经；无热仅恶寒，是发于阴经。”这是阴阳虚实之理，判断起来非常明确。
对于表虚证：表虚必然自汗多，伴有恶寒者，使用桂枝汤。若汗出过多，表虚不能护卫肌表，脉象微弱且恶风恶寒者，使用黄 建中汤。
桂枝汤方剂组成：桂枝（上等）、芍药（中等）、甘草（下等）。
煎服法：以上药材，加生姜三片，大枣二枚，水两盏，煎煮至一盏，稍温后服用。
对于阳虚证：阳气虚弱无法抵御风寒，身体虚弱、脉象虚弱且恶寒者，使用四君子汤加倍黄 、桂枝。虚损严重者，再加熟附子二、三片，或者使用黄 建中汤加附子。
对于火盛证：火邪极盛严重时，反而出现恶寒，这并非真寒，而是亢极反兼水化之象。用此法制约它，使用四物汤加入黄 、黄柏、黄连，火邪降下则寒象自然消除。
四物汤（方剂见血证篇）。
对于卫气不和证：气作为卫气，主要功能是护卫皮毛，温养肌肉，充实腠理。卫气不和，则腠理不坚固而导致恶寒者，使用调中益气汤加倍黄 、桂枝。
调中益气汤（方剂见气证篇）。
对于外感证：外感风寒，无汗，发热恶寒者，使用麻黄汤。有汗，恶风者，使用桂枝汤。平时感受寒邪，出现恶寒发热者，使用香苏散。
香苏散方剂组成：香附（上等）、苏叶（上等）、陈皮（中等）、甘草（下等）。
煎服法：以上药材切碎，一剂药，加生姜三片，枣二枚，水两盏，煎至八分，热服。
若加入川芎、白芷，名为芎芷香苏散。
对于肺病证：肺受火邪侵害而失去职能，不能固护腠理，出现洒淅恶寒者，使用甘桔汤加入酒制黄芩、山栀、麦门冬、五味子、酸枣仁。
[Verse] Chills (aversion to cold) arise from the deficiency of Yang Qi in the six channels. If accompanied by tremors and aversion to cold with excess Fire, it indicates a different pattern. In external contraction, the pulse is floating with pain in the head and nape. If caused by Lung Qi deficiency leading to shivering chills, there is no doubt.
[Discussion] Regarding chills: Some cases stem from Yang Qi deficiency causing loose interstices (pores), inability to resist Wind-Cold, and必然 profuse spontaneous sweating. Some cases result from extreme Fire excess, which paradoxically takes on Water characteristics to restrain itself, thus causing tremors and chills. Some cases are due to external contraction of Wind-Cold pathogens, presenting as exterior syndrome with a floating pulse, headache, and fever. Some cases occur when the Lung is constrained by Fire, becoming deficient and losing its governing function, resulting in shivering chills. Others are due to Wei Qi (Defensive Qi) deficiency failing to secure the interstices, or excessive sweating. Zhang Zhongjing stated: "Fever with chills indicates onset in Yang; absence of fever with chills indicates onset in Yin." This clearly distinguishes the principles of Yin/Yang and Deficiency/Excess.
For Exterior Deficiency Syndrome: Exterior deficiency inevitably leads to profuse spontaneous sweating. For those with chills, use Guizhi Tang (Cinnamon Twig Decoction). If sweating is excessive, and the exterior is too weak to protect the body, with a weak pulse and aversion to wind and cold, use Huangqi Jianzhong Tang (Astragalus Build the Middle Decoction).
Guizhi Tang (Cinnamon Twig Decoction): Composition: Guizhi (Cinnamon Twig, superior grade), Shaoyao (Peony Root, medium grade), Gancao (Licorice Root, inferior grade). Preparation: Add three slices of Shengjiang (Fresh Ginger) and two Jujubes (Chinese Dates), decoct with two cups of water until one cup remains. Take warm.
Xiao Jianzhong Tang (Minor Build the Middle Decoction): Is Guizhi Tang plus Yitang (Maltose), one he.
Huangqi Jianzhong Tang (Astragalus Build the Middle Decoction): Is Xiao Jianzhong Tang plus Huangqi (Astragalus Root) and Guizhi in equal parts.
For Yang Deficiency Syndrome: When Yang Qi is deficient and cannot resist Wind-Cold, with a weak body, deficient pulse, and chills, use Sijunzi Tang (Four Gentlemen Decoction) with increased doses of Huangqi (Astragalus Root) and Guizhi (Cinnamon Twig). For severe deficiency, add two or three slices of Shu Fuzi (Prepared Aconite Root), or use Huangqi Jianzhong Tang with Fuzi (Aconite Root).
Sijunzi Tang (Four Gentlemen Decoction) (See Spleen/Stomach section for formula).
For Fire Excess Syndrome: When Fire is extremely excessive, chills may appear paradoxically; this is not true cold, but an extreme condition taking on Water characteristics. To restrain it, use Siwu Tang (Four Substances Decoction) added with Huangqi (Astragalus Root), Huangbai (Phellodendron Bark), and Huanglian (Coptis Rhizome). Once Fire descends, the sensation of cold will naturally resolve.
Siwu Tang (Four Substances Decoction) (See Blood Disorders section for formula).
For Defensive Qi Disharmony Syndrome: Qi acts as Wei Qi (Defensive Qi), primarily protecting the skin and hair, warming the muscles, and solidifying the interstices. When Wei Qi is disharmonious, the interstices are not firm, leading to chills. Use Tiaozhong Yiqi Tang (Regulate the Middle and Boost Qi Decoction) with increased doses of Huangqi (Astragalus Root) and Guizhi (Cinnamon Twig).
Tiaozhong Yiqi Tang (Regulate the Middle and Boost Qi Decoction) (See Qi Disorders section for formula).
For External Contraction Syndrome: External contraction of Wind-Cold with no sweating, fever, and chills requires Mahuang Tang (Ephedra Decoction). With sweating and aversion to wind, use Guizhi Tang (Cinnamon Twig Decoction). For habitual exposure to Cold pathogens causing chills and fever, use Xiangsu San (Fragrant Perilla Powder).
Mahuang Tang (Ephedra Decoction) (See Fever section for formula).
Xiangsu San (Fragrant Perilla Powder): Composition: Xiangfu (Cyperus Rhizome, superior grade), Zisu Ye (Perilla Leaf, superior grade), Chenpi (Aged Tangerine Peel, medium grade), Gancao (Licorice Root, inferior grade). Preparation: Coarsely crush the herbs. For one dose, add three slices of Shengjiang (Fresh Ginger) and two Jujubes, decoct with two cups of water until eight-tenths remain. Take hot. If Chuanxiong (Ligusticum Rhizome) and Baizhi (Angelica Dahurica Root) are added, it is named Xiongzhi Xiangsu San (Ligusticum and Angelica Fragrant Perilla Powder).
For Lung Disease Syndrome: When the Lung is harmed by Fire pathogens, loses its function, fails to secure the interstices, and presents with shivering chills, use Ganjie Tang (Licorice and Platycodon Decoction) added with Jiuhuangqin (Scutellaria Root processed with wine), Shanzhi (Gardenia Fruit), Maimendong (Ophiopogon Tuber), Wuweizi (Schisandra Berry), and Suanzaoren (Ziziphus Seed).
Ganjie Tang (Licorice and Platycodon Decoction): Composition: Gancao (Licorice Root), Jiegeng (Platycodon Root) in equal parts. Preparation: Decoct with water and take.