背阳腹阴各异位。阳弱恶寒多在背。（素问云。背为阳。腹为阴。背恶寒者。阳弱也。）一则三阳合病生。（仲景云。
三阳合病。额上生汗。背恶寒者。是其证。）一则少阴寒在外。（仲景云。少阴病。得之一二日。口中和。背恶寒者。当
以灸。以附子汤主之。）欲识阴阳病不同。口和不和各分发。（仲景云。背恶寒。口不仁者。三阳合病也。又云。口中和。
背恶寒者。少阴也。）合病口燥并不仁。白虎抑阳是其对。（仲景以白虎治背寒。抑退阳也。）少阴口和须灸之。附子汤兼
阴自退。（解在上。）
厥有冷厥有热厥。脉证当须仔细别。冷厥才病四肢冷。脉但沉微身不热。（冷厥。初得病便觉四肢逆冷。脉沉而微。
身不甚热也。）足多挛卧并恶寒。引衣自覆仍不渴。（仲景云。凡厥者。阴阳之气不相顺接。便为厥。厥者手足厥冷是也。
故多足拘挛。外恶寒。引衣自覆不烦渴。）热厥身热头且痛。三四日内厥方发。半日之间热复回。扬手掷足烦躁列。（热
厥与冷厥。本自不同。冷厥。才病便厥。热厥。必四五日内方发。半日之间热复来也。扬手掷足。心中烦躁。）要之热深
厥亦深。热微厥亦微相侵。（仲景云。伤寒一二日。至四五日厥者。必发热。前厥者后必热。厥深。热亦深。厥微。热亦
微。厥应下之。而发汗者必口伤烂赤。）血气不通手足冷。医人不识却疑阴。其脉沉伏而更滑。头面有汗指甲温。急便下
之安可慢。不然疑似祸相仍。（沉伏而滑。伏热在内也。四肢虽厥。指爪必温。皆阳实也。急下之则愈。）又有正汗来相
逼。两手一手忽无脉。手足厥冷面不泽。细辛甘草汤脱厄。（朱肱云。忽然两手一手无脉。手足厥冷者。恐是正汗来。故
有此证。用细辛甘草汤以助其汗。汗出则可愈。）心下怔。（之成切。怔忪惧貌。）忪（职容切。心动不定。惊也。）厥有
水。脉紧厥时邪在里。（仲景云。伤寒。厥。而心下悸。先治其水。当与茯苓甘草汤以治厥。不尔。其水入胃。必利。又
云。病者手足冷。脉乍紧者。邪结在胸。心下满而烦。即不能食。病在胸中。当吐之。宜用瓜蒂散。）发热七八日身冷。
此名脏厥为难治。（仲景云。伤寒脉微而厥。至七八日。肤冷。其人不安。此为脏厥。非蛔厥也。蛔厥者。其人当吐。）
背部属阳，腹部属阴，二者位置各异。阳气虚弱导致的恶寒多发生在背部。（《素问》说：背为阳，腹为阴。背部恶寒，是因为阳气虚弱。）这种情况一则见于三阳合病。（张仲景说：三阳合病，额头出汗，背部恶寒的，就是这种证候。）一则见于少阴病，寒气在体表。（张仲景说：少阴病，得病一两天，口中平和不燥，背部恶寒的，应当用灸法治疗，并用附子汤主治。）想要识别阴阳病症的不同，关键在于口中是否干燥及症状分布的差异。（张仲景说：背部恶寒，口中感觉不仁（麻木/味觉减退）的，是三阳合病。又说：口中平和，背部恶寒的，是少阴病。）如果是三阳合病，伴有口燥和不仁，白虎汤抑制阳热是对症之方。（张仲景用白虎汤治疗背寒，以抑制退散阳热。）如果是少阴病，口中平和则需施灸，配合附子汤可使阴寒自退。（解释见上文。）
厥证有冷厥和热厥两种，脉象与证候必须仔细辨别。冷厥在发病初期四肢就发冷，脉象沉微，身体不发热。（冷厥，刚得病就觉得四肢逆冷，脉象沉而微弱，身体不太热。）足部多拘挛蜷卧并怕冷，拉过衣服遮盖自己，并且不口渴。（张仲景说：凡是厥证，都是阴阳之气不相顺接，导致厥。厥的表现就是手足厥冷。所以多见足部拘挛，外畏寒冷，拉衣自覆，心中不烦且口不渴。）热厥则身体发热且头痛，通常在发病后三四天内才出现厥冷。半天之间热度又恢复，表现为扬手掷足、烦躁不安。（热厥与冷厥，本来自不同。冷厥，刚得病就出现厥冷；热厥，必须经过四五天才发作。半天之间热度又回来。扬手掷足，心中烦躁。）总之，热邪越深，厥冷也越深；热邪轻微，厥冷也轻微，这是相互影响的。（张仲景说：伤寒一二天到四五天出现厥冷的，必定会发热，先前厥冷的后来必定发热。厥冷深，热邪也深；厥冷轻，热邪也轻。厥证应当用下法，如果误用发汗法，必定导致口腔受伤溃烂发红。）气血不通导致手足冷，医生如果不认识，却怀疑是阴证。但其脉象沉伏而且更兼滑象，头面部有汗，指甲温暖。此时应紧急使用下法，不可迟缓。否则疑似误诊，祸患接踵而至。（脉沉伏而滑，说明伏热在内。四肢虽然厥冷，但指爪必定温暖，这都是阳实证。紧急使用下法即可痊愈。）又有正汗来逼的情况，突然两手或一手无脉，手足厥冷面色无光泽，可用细辛甘草汤解除危难。（朱肱说：忽然两手或一手无脉，手足厥冷的，恐怕是正气之汗将至，所以有此证。用细辛甘草汤来助其发汗，汗出则可痊愈。）心下怔忪（惊恐貌），厥证有水饮，脉紧时邪气在里。（张仲景说：伤寒，厥，且心下悸动，先治疗水饮，应当给予茯苓甘草汤来治疗厥证。不然的话，水饮入胃，必定导致腹泻。又说：病人手足冷，脉象突然变紧的，邪气结聚在胸中，心下满闷而烦，即不能进食。病在胸中，应当用吐法，宜用瓜蒂散。）发热七八天后身体冰冷，这名叫脏厥，属于难治之症。（张仲景说：伤寒脉微而厥，到了七八天，皮肤冷，其人躁扰不安，这叫脏厥，不是蛔厥。蛔厥的病人，应当呕吐。）
The back belongs to Yang and the abdomen to Yin, occupying different positions. Chills due to weak Yang often occur on the back. (*Suwen* states: The back is Yang, the abdomen is Yin. Back chills indicate weak Yang.) This condition arises in two scenarios: one is *San Yang He Bing* (Combined Disease of the Three Yang Meridians). (Zhang Zhongjing states: In Combined Disease of the Three Yang Meridians, sweating on the forehead accompanied by back chills indicates this syndrome.) The other is *Shao Yin* disease, with cold pathogen on the exterior. (Zhang Zhongjing states: In *Shao Yin* disease, within one or two days of onset, if the mouth feels neutral [not dry] and there are back chills, moxibustion should be applied, and *Fuzi Tang* (Aconite Decoction) should be used as the primary treatment.) To distinguish between Yin and Yang syndromes, observe whether the mouth is neutral or dry and the distribution of symptoms. (Zhang Zhongjing states: Back chills with a sensation of numbness or loss of taste in the mouth indicate Combined Disease of the Three Yang Meridians. Conversely, a neutral mouth with back chills indicates *Shao Yin* disease.) If it is Combined Disease of the Three Yang Meridians with dry mouth and numbness, *Baihu Tang* (White Tiger Decoction) is the appropriate formula to suppress Yang heat. (Zhang Zhongjing uses *Baihu Tang* to treat back chills by suppressing and dissipating Yang heat.) If it is *Shao Yin* disease with a neutral mouth, moxibustion is required, and combined with *Fuzi Tang*, the Yin cold will recede naturally. (Explanation provided above.)
Jue syndrome (Cold Extremities) includes Cold Jue and Heat Jue; pulse and symptoms must be carefully differentiated. Cold Jue presents with cold limbs from the onset, a deep and thready pulse, and no significant body heat. (Cold Jue: Upon initial illness, the patient feels cold extremities; the pulse is deep and thready, and the body is not significantly hot.) The feet are often cramped and curled up, with aversion to cold, pulling clothes for cover, and no thirst. (Zhang Zhongjing states: All Jue syndromes result from the failure of Yin and Yang Qi to connect smoothly, leading to Jue. Jue is characterized by cold hands and feet. Thus, foot cramping, external aversion to cold, pulling clothes for warmth, absence of irritability, and lack of thirst are common.) Heat Jue presents with body heat and headache, with Jue typically developing after three or four days. Within half a day, heat returns, manifesting as tossing hands and feet and severe irritability. (Heat Jue differs fundamentally from Cold Jue. Cold Jue occurs immediately upon illness; Heat Jue develops only after four or five days, with heat returning within half a day. Tossing hands and feet indicates internal irritability.) Generally, the deeper the heat, the deeper the Jue; the milder the heat, the milder the Jue, as they influence each other. (Zhang Zhongjing states: In Shanghan, if Jue appears between the first/fifth day, fever will follow previous Jue. Deep Jue implies deep heat; mild Jue implies mild heat. Jue should be treated with purgation; misusing diaphoresis will cause oral ulcers and redness.) When Qi and Blood stagnation causes cold extremities, physicians who fail to recognize this may mistakenly suspect a Yin syndrome. However, if the pulse is deep, hidden, and slippery, with sweating on the head and face, and warm fingernails, urgent purgation is required without delay. Otherwise, diagnostic confusion will lead to further calamity. (Deep, hidden, and slippery pulses indicate latent heat within. Although limbs are cold, fingernails are warm, indicating excess Yang syndrome. Urgent purgation leads to recovery.) Another scenario involves the approach of genuine sweat, where suddenly one or both arms lose their pulse, with cold extremities and a dull complexion. *Xixin Gancao Tang* (Asarum and Licorice Decoction) can resolve this crisis. (Zhu Gong states: Sudden loss of pulse in one or both arms with cold extremities suggests impending genuine sweat. Use *Xixin Gancao Tang* to assist sweating; recovery follows sweating.) Heart palpitations (*Zheng Tong*) accompany Jue with water retention; when the pulse is tight, the pathogen is interior. (Zhang Zhongjing states: In Shanghan, Jue with epigastric palpitations requires prior treatment of water retention using *Fuling Gancao Tang* (Poria and Licorice Decoction); otherwise, water entering the stomach causes diarrhea. Also, cold extremities with a sudden tight pulse indicate pathogen knotting in the chest, causing epigastric fullness, irritability, and anorexia. Since the disease is in the chest, emesis is indicated, using *Gua Di San* (Melon Seed Powder).) Fever lasting seven to eight days followed by cold body is named Zang Jue (Viscera Jue), which is difficult to treat. (Zhang Zhongjing states: In Shanghan, a faint pulse with Jue progressing to skin coldness and restlessness after seven to eight days is Zang Jue, distinct from Hui Jue (Roundworm Jue). Patients with Hui Jue typically vomit.)