虚烦者。其人无大热。心中温温欲吐。而又不能吐。致内扰而烦。然名为虚烦。而其证有因
于虚者。亦有因于实者。皆邪热传里之候。宜分别施治。有邪热传入少阳而发烦者。经云。
伤寒五六日。往来寒热。心烦喜呕。或胸中烦而不呕。小柴胡汤主之。盖少阳既不可发汗。
而里未实又不可下。故以小柴胡汤两和其表里。表里俱和。则烦自除矣。
又有阳热之气。下陷入胸中。而作虚烦。宜用吐法以宣其热。如经云。发汗吐下后。虚
烦不
得眠。若剧者。必反复颠倒。心中懊 。栀子豉汤主之。若少气者。栀子甘草豉汤主之。若
呕者。栀子生姜豉汤主之。心烦腹满。卧起不安者。栀子浓朴汤主之。又伤寒。医以丸药大
下之。身热不去微烦者。栀子干姜汤主之。此皆取吐之剂。宜按其兼证。分别加减。其吐中
有发散之义。足以升举下陷之阳邪。此乃吐虚烦之大法。至于烦之实者。非大吐不能除。如
经云。病患手足厥冷。脉下紧者。邪结在胸中。心中满而烦。饥不能食者。病在胸中。当吐
之。宜瓜蒂散。则同一取吐。而轻重又不同矣。
病在胸中者当吐。其胃实者。又非吐法所能除。经云。阳明病不吐不下心烦者。调胃承
气汤
主之。所谓阳明病者。胃家实是也。与调胃承气以涤其烦。是于微利之中。仍寓和解之义也
。
烦热者。因热而烦。其所患皆阳热之证。无阴证也。至虚烦。则有阳病。又有阴病。经
云。少阴病二三日。心中烦不得卧者。黄连阿胶汤主之。少阴病胸满心烦者。猪肤汤主之。又云少
阴病下利六七日。咳而呕渴。心烦不得眠者。猪苓汤主之。盖少阳为阳中之枢。少阴为阴中
之枢。热伤少阴。津液被耗。邪热内扰。故各以其兼证。施种种存阴涤烦之法。亦和解之义
也。至阴寒证。则反以烦为可转阳之机。故又云少阴病恶寒而蜷。时自烦欲去衣被者。为可
治也。
少阳病有烦而悸者。此属胃。胃不和则烦而悸。和胃为主。又有悸而烦者。如经云伤寒二三
日。心中悸而烦者。小建中汤主之。是也。大凡先烦而后悸者。属实。先悸而后烦者。属虚
。补虚泄实。治各不同矣。
别有所谓懊 者。比烦而甚者也。宜因证而分别吐下。如经云。阳明病。其外有热。手足
温。不结
胸。心中懊 。饥不能食。但头汗出者。宜栀子豉汤。此宜吐者也。又经云。阳明病。心中
懊而烦。胃有燥矢者。可攻。此宜下者也。更有因蛔厥而时自烦者。经云。伤寒蛔厥者。
其人当吐蛔。病者静而复时烦者。此为藏寒。蛔上入其膈。故烦。须臾复止。得食而呕。又
烦者。蛔闻食臭出。其人当自吐蛔。蛔厥者。乌梅丸主之。此得之于时烦时止。得食复烦。
与热郁者不同。临证时当细辨也。
有病已愈而犹烦者。经云。吐利发汗。脉平。小烦者。以新虚不胜谷气故也。又云。病
人脉
已解而日暮微烦。以脾胃尚弱。不能消谷。故令微烦。损谷即愈。此可勿药。即药亦不过平
调脾胃。慎勿再与泄热。重伤胃气也。
虚烦，是指患者体内没有明显的大热，但心中感到温热不适、想要呕吐却又吐不出来，导致内部扰动而产生烦躁。虽然名为“虚烦”，但其病因既有因正气虚弱所致者，也有因邪气实盛所致者，均属于邪热传入体内的表现，应当分别情况进行治疗。
若有邪热传入少阳经而引发烦躁的，《伤寒论》记载：“伤寒五六日，出现往来寒热（忽冷忽热），心烦且喜欢呕吐；或者仅胸中烦躁而不呕吐，用小柴胡汤主治。”这是因为少阳病既不可发汗，里证也未结实不可攻下，所以用小柴胡汤来调和表里。表里调和，烦躁自然消除。
又有阳气热邪之气，因误治下陷于胸中，从而形成虚烦，适宜用涌吐法来宣散其热邪。如《伤寒论》记载：经过发汗、催吐或泻下治疗后，出现虚烦、失眠；如果病情严重，必定翻来覆去、坐卧不安，心中郁闷难受（懊憹），用栀子豉汤主治。若兼有气短者，用栀子甘草豉汤主治。若兼有呕吐者，用栀子生姜豉汤主治。若心烦伴腹部胀满、睡卧不宁者，用栀子厚朴汤主治。另外，患伤寒后，医生误用丸药猛烈泻下，导致身热不退、轻微烦躁者，用栀子干姜汤主治。这些方剂都属于取吐之剂，应根据兼夹症状进行加减。其中吐法蕴含发散之意，足以升举下陷的阳邪，这是治疗虚烦的大法。至于属于实证引起的烦躁，非剧烈涌吐不能消除。如《伤寒论》记载：患者手足冰冷，脉象沉紧，说明邪气结聚在胸中，心中胀满且烦躁，饥饿却无法进食，病位在胸中，应当用涌吐法，宜用瓜蒂散。同样是取吐法，但轻重程度有所不同。
病位在胸中的应当用吐法；若胃腑实热，则不是吐法所能去除的。《伤寒论》记载：“阳明病，未经过催吐或泻下而出现心烦的，用调胃承气汤主治。”所谓阳明病，就是胃家实（胃肠燥热结实）。给予调胃承气汤以涤荡热邪，这是在轻微通下的过程中，仍寓含和解之意。
烦热，是因为热邪而导致烦躁，所患的都是阳热证，没有阴证。至于虚烦，则有阳病和阴病之分。《伤寒论》记载：“少阴病两三天，心中烦躁、无法躺卧的，用黄连阿胶汤主治。”“少阴病胸满心烦的，用猪肤汤主治。”又记载：“少阴病腹泻六七天，咳嗽、呕吐、口渴、心烦、无法入睡的，用猪苓汤主治。”这是因为少阳是阳气的枢纽，少阴是阴气的枢纽。热邪损伤少阴，津液被消耗，邪热内扰，所以根据各自的兼症，采取各种保存阴液、清除烦躁的方法，这也属于和解的意义。至于阴寒证，反而将烦躁视为阳气回复的转机，所以说：“少阴病恶寒且身体蜷缩，偶尔自行烦躁想要去掉衣被的，是可以治疗的。”
少阳病伴有烦躁且心悸的，这属于胃病，胃不和则烦躁且心悸，治疗以调和胃气为主。又有先心悸而后烦躁的，如《伤寒论》记载：“伤寒两三天，心中悸动且烦躁的，用小建中汤主治。”一般来说，先烦躁而后心悸的，属实证；先心悸而后烦躁的，属虚证。补虚与泄实，治疗方法各不相同。
另有称为“懊憹”的症状，比烦躁更为严重，应当根据证候分别采用吐法或下法。如《伤寒论》记载：“阳明病，体表有热，手足温暖，未形成结胸，心中懊憹，饥饿却不想吃东西，只有头部出汗的，宜用栀子豉汤。”这是适宜用吐法的。又记载：“阳明病，心中懊憹且烦躁，胃中有燥屎积结的，可以攻下。”这是适宜用下法的。更有因蛔虫厥逆而时常自发的烦躁，《伤寒论》记载：“患伤寒的蛔厥病患者，应当吐出蛔虫。病人安静时却时而烦躁，这是因为内脏有寒，蛔虫上行进入膈部，所以引起烦躁，片刻后又停止，进食后呕吐，再次烦躁，是因为蛔虫闻到食物气味而出，病人应当自行吐出蛔虫。蛔厥证，用乌梅丸主治。”这是由于时烦时止、进食后复烦，与热邪郁结不同，临证时必须仔细辨别。
有病已痊愈但仍感烦躁的，《伤寒论》记载：“经过吐、利、发汗后，脉象平和，仅有轻微烦躁的，是因为新近体虚，不胜受纳谷气所致。”又记载：“病人脉象已解，但在傍晚时分轻微烦躁，是因为脾胃尚弱，不能消化食物，所以导致轻微烦躁，减少饮食即可痊愈。”这种情况可以不用服药，即使用药也不过是平和调理脾胃，切勿再用清热泻下药，以免重伤胃气。
Xu Fan (Deficiency Irritability) refers to a condition where the patient has no significant high fever in the body, but feels a warm discomfort in the chest, with a desire to vomit that cannot be fulfilled, leading to internal disturbance and irritability. Although named "Deficiency Irritability," its etiology includes both cases caused by deficiency of healthy Qi and those caused by excess pathogenic factors. All are manifestations of pathogenic heat transmitting into the interior, and treatment should be differentiated accordingly.
If irritability arises from pathogenic heat transmitting to the Shaoyang (Lesser Yang) channel, as stated in the classic text: "In cold damage after five or six days, there is alternating chills and fever, irritability, and a tendency to vomit; or only irritability in the chest without vomiting, Xiao Chai Hu Tang (Minor Bupleurum Decoction) is the primary formula." This is because Shaoyang disease is neither suitable for sweating nor for purging if the interior is not yet solid. Therefore, Xiao Chai Hu Tang harmonizes both the exterior and interior. Once the exterior and interior are harmonized, the irritability naturally resolves.
In other cases, Yang-heat Qi sinks into the chest due to improper treatment, causing Xu Fan. The emetic method should be used to disperse the heat. As stated in the classic text: "After sweating, vomiting, or purging, if there is Xu Fan and insomnia; if severe, the patient tosses and turns restlessly and feels deep inner distress (Ao Nao), Zhi Zi Chi Tang (Gardenia and Fermented Soybean Decoction) is indicated. If there is shortness of breath, Zhi Zi Gan Cao Chi Tang (Gardenia, Licorice, and Fermented Soybean Decoction) is indicated. If there is vomiting, Zhi Zi Sheng Jiang Chi Tang (Gardenia, Ginger, and Fermented Soybean Decoction) is indicated. If there is irritability accompanied by abdominal fullness and restlessness day and night, Zhi Zi Hou Po Tang (Gardenia and Magnolia Bark Decoction) is indicated. Furthermore, if after cold damage, a physician mistakenly uses strong pill-based purgatives, resulting in persistent slight fever and mild irritability, Zhi Zi Gan Jiang Tang (Gardenia and Dried Ginger Decoction) is indicated." These formulas belong to the category of emetics. Modifications should be made based on accompanying symptoms. The emetic method contains the principle of dispersing, sufficient to raise the sinking Yang pathogen. This is the general principle for treating Xu Fan. For irritability caused by excess patterns, only vigorous emesis can resolve it. As stated in the classic text: "If the patient's hands and feet are cold, the pulse is tight below, indicating pathogenic accumulation in the chest, with chest fullness and irritability, hunger but inability to eat, the disease is in the chest and should be treated with emesis using Gua Di San (Melon Sepal Powder)." Thus, while both use emesis, their severity differs.
When the disease is in the chest, emesis is indicated. However, if there is stomach excess (Yangming Excess), emesis alone cannot resolve it. As stated in the classic text: "In Yangming disease, if irritability occurs without prior vomiting or purging, Tiao Wei Cheng Qi Tang (Regulate the Stomach and Direct to the Qi Decoction) is indicated." Yangming disease refers to "Stomach Home Excess" (excess heat and dryness in the stomach and intestines). Administering Tiao Wei Cheng Qi Tang clears the irritability through mild purgation, still embodying the principle of harmonization.
Fan Re (Irritable Heat) is irritability caused by heat, representing all Yang-heat patterns, with no Yin patterns involved. In contrast, Xu Fan includes both Yang and Yin diseases. As stated in the classic text: "In Shaoyin disease lasting two or three days, if there is heart irritability and inability to lie down, Huang Lian E Jiao Tang (Coptis and Donkey-Hide Gelatin Decoction) is indicated. If Shaoyin disease presents with chest fullness and irritability, Zhu Fu Tang (Pig Skin Decoction) is indicated. Also, if Shaoyin disease involves diarrhea for six or seven days, accompanied by cough, vomiting, thirst, irritability, and insomnia, Zhu Ling Tang (Polyporus Decoction) is indicated." This is because Shaoyang is the pivot of Yang, and Shaoyin is the pivot of Yin. Heat damaging Shaoyin consumes body fluids, and pathogenic heat disturbs the interior. Therefore, various methods to preserve Yin and clear irritability are applied according to accompanying symptoms, which also falls under the meaning of harmonization. Regarding Yin-cold patterns, irritability is seen as a sign of Yang recovery. Thus, it is said: "In Shaoyin disease, if there is aversion to cold and curling up, but occasional self-induced irritability with a desire to remove clothing and blankets, this indicates a treatable condition."
In Shaoyang disease, if there is irritability accompanied by palpitations, this belongs to the Stomach. When the Stomach is disharmonious, irritability and palpitations occur; treatment focuses on harmonizing the Stomach. Conversely, if palpitations precede irritability, as stated in the classic text: "In cold damage after two or three days, if there is heart palpitation and irritability, Xiao Jian Zhong Tang (Minor Construct the Middle Decoction) is indicated." Generally, irritability preceding palpitations indicates an Excess pattern, while palpitations preceding irritability indicate a Deficiency pattern. Tonifying deficiency and draining excess require different treatments.
Another symptom described is "Ao Nao" (Deep Inner Distress), which is more severe than irritability. Treatment should differentiate between emesis and purging based on the syndrome. As stated in the classic text: "In Yangming disease, if there is external heat, warm hands and feet, no formation of Jie Xiong (Chest Binding), heart Ao Nao, hunger but inability to eat, and sweating only on the head, Zhi Zi Chi Tang (Gardenia and Fermented Soybean Decoction) is indicated." This requires emesis. Also: "In Yangming disease, if there is heart Ao Nao and irritability, and dry fecal matter exists in the stomach/intestines, purging is possible." This requires purging. Additionally, there is irritability caused by Ascariasis Jue (Roundworm Cold-Reversal). As stated in the classic text: "In cold damage with roundworm Jue, the patient should vomit roundworms. The patient is quiet but occasionally irritable, indicating internal cold. The roundworms ascend to the diaphragm, causing irritability, which stops after a moment. Vomiting occurs after eating, followed by further irritability, as the roundworms emerge smelling food, and the patient may vomit roundworms spontaneously. Roundworm Jue is treated with Wu Mei Wan (Mume Pill)." This differs from heat stagnation due to intermittent irritability that recurs after eating. Careful differentiation is required during clinical practice.
For patients who have recovered but still experience irritability, as stated in the classic text: "After vomiting, purging, or sweating, if the pulse is peaceful but there is slight irritability, it is because the newly weakened body cannot handle the grain qi." Also: "If the patient's pulse has resolved but there is slight irritability at dusk, it is because the Spleen and Stomach are still weak and cannot digest food, causing slight irritability. Reducing food intake leads to recovery." In such cases, medication is unnecessary. Even if medication is used, it should only gently regulate the Spleen and Stomach. One must avoid using heat-clearing purgatives again to prevent further damaging Stomach Qi.