内热为烦，外热为躁，烦出于肺，躁出于肾，热传肺肾，则烦躁俱作。然烦为阳，属有根之火，故但频
不躁，及先烦后躁者，皆易治。躁为阴，系无根之火，故但躁不烦，及先躁后烦者，皆难治。伤寒论中有微烦、
反烦、复烦、烦满、烦热、烦渴、胸烦、心烦、虚烦、大烦，皆热也。先烦渐躁者为烦躁，先躁复烦者为躁烦。
烦多属热，亦有阴寒而烦者，伤寒热在表而烦，宜散。桂枝汤。在里而烦，宜下。承气汤。在半表半里而烦，
宜和。小柴胡汤。在胸膈以上而烦，宜吐。栀豉汤。其阴寒而烦，则有恶寒蜷卧，及下利厥逆，吐蛔之症，
宜温。温用四逆汤，蛔用乌梅丸。若烦而足冷脉沉微者，此阴症之烦也，急用参附热剂温之。悸而烦为虚，建
中汤。烦而悸为热，调胃承气汤。如内伤阴虚火动而烦，宜生脉散加生地黄、熟地黄、茯神、枣仁。或不得
卧而烦，朱砂安神丸。若不烦而躁，欲卧泥水中，但饮水不得入口者，此为阴盛格阳。《活人书》用霹雳散，
或附子理中汤、附子四逆汤。其脉必沉细疾，肢体厥冷，躁扰不欲饮水是也。若误认为热，投以凉药，顷刻死
矣。伤寒有邪在表而烦躁者，脉浮紧，发热身痛，汗之则定。大青龙汤。有邪在里而烦躁者，脉数实有力，
不大便，绕脐痛，下之则定。承气汤。有阳虚而烦躁者，汗下后，昼烦躁，
夜安静，脉沉微，身无大热。干姜附子汤。有阴盛而烦躁者，少阴症，吐利手足冷，烦躁欲死。吴茱萸汤。
更有阴中伏阳烦躁者，头疼身温，指末冷，胸满恶心，脉沉伏，按至骨若有力，须破散阴气，导达真火。
《本事》用破阴丹。阴中伏阳症，用热药助阳，则为阴所隔绝，不能导引真阳。用冷药，则所伏真火，立
见消亡，用破阴丹，使水升火降，得汗而解矣。其杂症虚烦，因津涸燥结而烦者，人参固本丸加枣仁、竹叶。
因血虚烦渴，至夜躁热尤甚者，当归补血汤。因肾水下竭，心火上炎而烦者，生料六味丸煎服。病后余热欲吐，
虚烦不安者，人参竹叶汤、竹茹汤。病久烦热不止，六味汤加枣仁。肥人虚烦不眠为痰，温胆汤。烦而溺涩
者，五苓散加滑石。烦而呕者，橘皮汤。
《活人书》曰∶阴气少，阳气胜，则热而烦，故太阳经伤风，多烦而躁也。戴元礼曰∶烦躁，阴阳经皆
有之，阳明经有燥屎故烦，此当下。承气汤。太阳经已得汗，渴烦者，五苓散。少阳胸满而烦，小柴胡汤。
阴烦，少阴为多，由阳气传入阴经，阴得阳而烦，自利而渴，烦不眠者，辰砂五苓散。若非是阳气传阴，阴气
犯阴经，吐利，手足厥冷而烦。经云∶阳虚阴乘之，故烦。又云∶阴盛发躁，欲坐井中。吴茱萸汤，甚者四逆
汤加葱白二茎。外有虚烦一症，乃病愈后阴阳未复，时发烦热。竹叶石膏汤。
李东垣曰∶血虚发躁，烦渴引饮，至夜尤甚，脉洪大，按之无力。当归补血汤。若以白虎汤服之，则误矣。
若脉浮大，按之散，此虚极将脱。人参生脉散。
许学士治李信道，六脉沉伏不见，按至骨，若有力，头痛身温，烦躁指冷，胸中满，恶心，此阴中伏阳，
仲景法中无此症。用冷药则所伏真火愈消，即用热剂助阳，先为阴遏，绝不能导引真阳，须用破散阴气，
导达真火之药，使水升火降，然后得汗而解。与破阴丹二百粒，作一服，冷盐汤下。不时烦躁狂热，手足躁扰，
其家大惊。许曰∶俗所谓换阳也。须臾稍定，略睡身汗凉解。又治一人，伤寒身热，无汗谵语、下后大便不
通三日矣，非躁非烦、终夜不得卧，时发叹息。许曰∶此懊 怫郁二症俱作，由胃中有燥屎也。与承气汤下
之，愈。《素问》云∶胃不和则卧不
安。仲景云∶阳明病下之，心中懊 微烦，有燥屎者，可攻。又云∶有微热，怫郁不卧者，有燥屎。又云∶胃
中燥，大便坚，必谵语，皆承气汤症也。
Internal heat manifests as *fan* (restlessness/irritability), while external heat manifests as *zao* (agitation/restlessness). *Fan* originates from the Lung, and *zao* originates from the Kidney; if heat transmits to the Lung and Kidney, both *fan* and *zao* occur simultaneously. However, *fan* belongs to Yang and is fire with a root; therefore, cases presenting only frequent *fan* without *zao*, or *fan* preceding *zao*, are easy to treat. *Zao* belongs to Yin and is fire without a root; therefore, cases presenting only *zao* without *fan*, or *zao* preceding *fan*, are difficult to treat. In the *Shanghan Lun* (Treatise on Cold Damage Disorders), terms such as slight *fan*, contrary *fan*, recurring *fan*, *fan* with fullness, *fan* with heat, *fan* with thirst, chest *fan*, heart *fan*, deficiency *fan*, and severe *fan* all belong to heat syndromes. When *fan* gradually turns into *zao*, it is called *fan-zao*; when *zao* reverts to *fan*, it is called *zao-fan*.
*Fan* mostly belongs to heat syndromes, but there are also cases of *fan* caused by Yin-cold. In cold damage disorders, if heat is in the Exterior causing *fan*, dispersing methods should be used, such as Guizhi Tang (Cinnamon Twig Decoction). If heat is in the Interior causing *fan*, purgative methods should be used, such as Chengqi Tang (Gastrointestinal Releasing Decoction). If heat is in the Half-Exterior Half-Interior causing *fan*, harmonizing methods should be used, such as Xiaochaihu Tang (Minor Bupleurum Decoction). If heat is above the chest and diaphragm causing *fan*, emetic methods should be used, such as Zhichi Tang (Gardenia and Fermented Soybean Decoction). Regarding *fan* caused by Yin-cold, symptoms include aversion to cold with curling up, diarrhea with cold limbs, and vomiting of roundworms; warming methods should be used. For warming, Sini Tang (Four Reversal Decoction) can be used; for vomiting roundworms, Wumei Wan (Mume Pill) is indicated. If *fan* is accompanied by cold feet and a deep, faint pulse, this is *fan* of a Yin syndrome, requiring urgent treatment with a hot decoction containing Renshen (Ginseng) and Fuzi (Prepared Aconite Root) to warm the body. Palpitations accompanied by *fan* indicate deficiency, treated with Jiantong Tang (Middle-Regulating Decoction); *fan* accompanied by palpitations indicates heat, treated with Tiaowei Chengqi Tang (Stomach-Regulating Gastrointestinal Releasing Decoction). If internal injury leads to Yin deficiency with hyperactive fire causing *fan*, Shengmai San (Life-Preserving Powder) added with Shengdihuang (Rehmanniae Radix), Shudihuang (Rehmanniae Radix Preparata), Fushen (Poria with Hostwood), and Zaoren (Ziziphi Spinosae Semen) should be used. Alternatively, for insomnia accompanied by *fan*, Zhusha Anshen Wan (Cinnabar Calming the Spirit Pill) is used. If there is no *fan* but only *zao*, with a desire to lie in mud or water, yet unable to swallow water, this is a syndrome of extreme Yin cold repelling floating Yang. The *Huanren Shu* (Book of Vitality) recommends Pili San (Thunderbolt Powder), or Fuzi Lizhong Tang (Aconite Regulate the Middle Decoction) and Fuzi Sini Tang (Aconite Four Reversal Decoction). The pulse will necessarily be deep, fine, and rapid, with cold limbs, agitation, and an unwillingness to drink. If mistakenly diagnosed as heat and treated with cooling herbs, death will ensue instantly.
In cold damage disorders, if pathogens are in the Exterior causing *fan-zao*, the pulse is floating and tight, with fever and body pain; sweating will resolve it, using Daqinglong Tang (Major Blue-green Dragon Decoction). If pathogens are in the Interior causing *fan-zao*, the pulse is rapid, full, and forceful, with constipation and periumbilical pain; purging will resolve it, using Chengqi Tang. If Yang deficiency causes *fan-zao*, after sweating or purging, there is daytime irritability and nighttime calmness, a deep and faint pulse, and no significant body heat; Ganjiang Fuzi Tang (Dried Ginger and Aconite Decoction) is used. If extreme Yin excess causes *fan-zao*, it is a Shaoyin syndrome with vomiting, diarrhea, cold limbs, and severe agitation desiring death; Wuzhuyu Tang (Evodia Decoction) is used. Furthermore, there is *fan-zao* due to hidden Yang within Yin, characterized by headache, warm body, cold fingertips, chest fullness, nausea, and a deep, hidden pulse that feels forceful when pressed to the bone. One must break up the Yin qi and guide the true fire. The *Ben Shi Fang* (Formulas of Worth) recommends Poyin Dan (Yin-Breaking Pill). For hidden Yang within Yin, using hot herbs to assist Yang will be blocked by Yin qi, preventing the guidance of true Yang; using cold herbs will cause the hidden true fire to perish immediately. Using Poyin Dan allows water to rise and fire to descend, resolving the condition through sweating.
For miscellaneous diseases, deficiency *fan* caused by fluid exhaustion and dryness accumulation is treated with Renshen Guben Wan (Ginseng Root-Nourishing Pill) added with Zaoren and Zhuye (Bamboo Leaves). Deficiency *fan* and thirst due to blood deficiency, with worse night-time agitation, is treated with Danggui Buxue Tang (Angelica Tonifying Blood Decoction). *Fan* due to depletion of Kidney water and flaming up of Heart fire is treated with Shengliao Liuwei Wan (Six-Ingredient Pill with Added Ingredients) decocted and taken orally. After illness, residual heat causing nausea, deficiency *fan*, and uneasiness is treated with Renshen Zhuye Tang (Ginseng and Bamboo Leaf Decoction) and Zhuru Tang (Bamboo Shavings Decoction). Persistent *fan-heat* after a long illness is treated with Liuwei Tang (Six-Ingredient Decoction) added with Zaoren. Deficiency *fan* and insomnia in obese individuals due to phlegm is treated with Wendan Tang (Warm the Gallbladder Decoction). *Fan* with difficult urination is treated with Wuling San (Five-Ingredient Powder) added with Huashi (Talcum). *Fan* with vomiting is treated with Chupi Tang (Tangerine Peel Decoction).
The *Huanren Shu* states: When Yin qi is scant and Yang qi prevails, heat and *fan* occur; thus, Wind-strike of the Taiyang channel often presents with *fan* and *zao*. Dai Yuanli stated: *Fan-zao* occurs in both Yin and Yang channels. In the Yangming channel, *fan* is due to dry feces, requiring purgation with Chengqi Tang. In the Taiyang channel, after sweating, if thirst and *fan* persist, use Wuling San. In the Shaoyang channel, chest fullness with *fan* is treated with Xiaochaihu Tang. Yin *fan* is common in the Shaoyin channel, occurring when Yang qi transmits to the Yin channel; Yin receiving Yang causes *fan*, spontaneous diarrhea, thirst, and sleepless *fan*, treated with Chencha Wuling San (Cinnabar Five-Ingredient Powder). If not Yang transmitting to Yin, but Yin qi invading the Yin channel, causing vomiting, diarrhea, cold limbs, and *fan*: The classics state, "Yang deficiency allows Yin to invade, hence *fan*." It also states, "Extreme Yin excess causes agitation, desiring to sit in a well." Treat with Wuzhuyu Tang; for severe cases, Sini Tang added with two stalks of Congbai (Scallion White). Additionally, there is a deficiency *fan* syndrome where, after recovery, Yin and Yang have not yet restored, causing intermittent heat and *fan*, treated with Zhuye Shigao Tang (Bamboo Leaf and Gypsum Decoction).
Li Dongyuan stated: Blood deficiency causing agitation, *fan* and thirst with drinking preference, worse at night, with a surging pulse that is empty upon pressure, is treated with Danggui Buxue Tang. Using Baihu Tang (White Tiger Decoction) would be a mistake. If the pulse is floating and large but scattered upon pressure, indicating extreme deficiency about to collapse, use Renshen Shengmai San (Ginseng Life-Preserving Powder).
Scholar Xu treated Li Xindao, whose six pulses were deep and hidden, feeling forceful when pressed to the bone, with headache, warm body, agitation, cold fingers, chest fullness, and nausea. This is hidden Yang within Yin, a syndrome not found in Zhang Zhongjing's methods. Cold herbs would extinguish the hidden true fire; hot herbs assisting Yang would first be blocked by Yin, failing to guide true Yang. One must use herbs to break Yin qi and guide true fire, allowing water to rise and fire to descend, resolving via sweat. He administered 200 pills of Poyin Dan (Yin-Breaking Pill) in one dose, taken with cold salt water. The patient experienced intermittent severe agitation and heat, with restless limbs, alarming the family. Xu said, "This is what laypeople call 'changing Yang'." Shortly after, the patient calmed slightly, slept, and then sweated, cooling and recovering. Xu also treated another patient with cold damage, fever, no sweat, delirious speech, and constipation for three days post-purgation. The patient was neither agitated nor irritable, could not sleep all night, and sighed frequently. Xu said, "This is simultaneous Ao-nao (mental depression/distress) and Fuyu (oppression/stagnation), caused by dry feces in the stomach." He administered Chengqi Tang to purge, resulting in recovery. The *Suwen* states: "When the Stomach is disharmonious, sleep is uneasy." Zhang Zhongjing stated: "After purging Yangming disease, if there is mental distress and slight *fan* with dry feces, attack [with purgatives]." He also stated: "With slight heat and oppression preventing sleep, there are dry feces." And: "Dryness in the Stomach, hard stools, inevitably lead to delirium." All these are indications for Chengqi Tang.