（附项强）
太阳之为病。脉浮。头项强痛。而恶寒。是头项强痛专属太阳证。然他经亦互见。特太
阳其专主耳。凡邪之自外而入者。必主头痛。如经云。太阳病头痛发热身疼腰痛骨节疼痛恶风无
汗而喘者。麻黄汤主之。太阳病头痛发热汗出恶风者。桂枝汤主之。此与发热同机。风寒之
邪。自外而入。其脉主浮。故可发之使从汗解也。
其有不从太阳而从少阳者。经云。伤寒脉弦细。头痛发热者。属少阳。少阳不可发汗。
此属胃。胃和则愈。胃不和则烦而悸。盖弦为少阳定脉。其头痛特邪之外溢于太阳。而非太阳之
自病。故仲景特申发汗之禁。又太阳与少阳并病。头项强痛。或眩冒。时如结胸。心下痞硬
者。慎不可汗。而亦不可下。汗下俱不可。而从少阳和解之法。仲景虽不言。在人因证善会
矣。
阳明病尤忌发汗。经云。伤寒六七日。不大便头痛有热者。与承气汤。其小便清者。知
不
在里仍在表也。当须发汗。若头痛者必衄。此言风寒之邪。由表而入。热未入里。仍宜汗解。
既入于里。则宜以承气汤下之矣。由此推之。湿热之邪。本在于里。而外溢于表。其初起每
见头痛证。当以清里为主。微兼透表。里和则表自解。若徒与攻表。非但头痛不减。恐里
证增剧矣。
太阴病亦有头痛者。经云。霍乱头痛发热身疼痛。热多欲饮水者。五苓散主之。寒多不
用水
者。理中汤主之。霍乱。太阴证也。头痛发热。是阴病有转阳之机。惟亟去其里寒。则病出
于阳而可治矣。
少阴一经。与太阳相表里。太阳之脉浮。少阴之脉沉。经云病发热头痛脉反沉。若不瘥
。身体疼痛。宜四逆汤。盖沉非太阳之脉。即不得同太阳发表之例。而与以大发其汗矣。
太阴少阴。其脉上至颈胸中而还。不循于头。应无头痛证。然阴阳出入。互相输应。其
机正妙
于转。不能呆执而论。至厥阴之脉。循喉咙之后。上入颃颡。连目 。上出额。与督脉会于
巅。病亦有头痛者。如经云。干呕吐涎沫头痛者。吴茱萸汤主之是也。厥阴头痛。往往直升
巅顶。其有痛甚入连于脑。而手足寒者不治。
太阳经病不解。转传入府者。其人头痛而小便不利。治当不从经解。而从府解。如经云
。服
桂枝汤。或下之。仍头项强痛翕翕发热无汗心下满微痛小便不利者。桂枝去桂加茯苓白术汤
主之。盖所以运胸中之阳。以化寒水之气。使从小便则解。故曰。小便利则愈也。由是推之
。其有热结于府。头痛小便不利。而又加以口渴。则宜以甘寒泻其府热。而头痛自愈。其法
又可会矣。
太阳之邪并于上。则头项强痛。并于下则项背强痛。经云。太阳病项背强KT KT 反
汗出恶风者。桂枝加葛根汤主之太阳病项背强KT KT 无汗恶风者。葛根汤主之。此以有汗无汗
分别风寒与发热同义。又经云。病者身热足寒。颈项强急。恶寒。时头热面赤。目脉赤。独
头面摇。卒口噤背反张者。痉病也，另详痉门。又结胸者。项亦强如柔痉状。下之则和。宜
大
陷胸丸。盖气结于胸。则项牵连而强。故下之则和。此虽见项强证。而其邪又不关太阳也。
（附注：项强）
太阳病的主要特征是：脉象浮，头部和颈部僵硬疼痛，并且怕冷。这说明头项强痛是太阳病的专属证候。然而，其他经络的病证中也会偶尔出现这种情况，只是太阳病最为典型罢了。凡是外邪从体表侵入的，必然会导致头痛。正如经典所说：“太阳病，出现头痛、发热、身体疼痛、腰痛、骨节疼痛、怕风、无汗且气喘的症状，应当用麻黄汤治疗。”“太阳病，出现头痛、发热、出汗、怕风的症状，应当用桂枝汤治疗。”这些情况与发热机理相同，风寒之邪从外部侵入，脉象表现为浮，因此可以通过发汗的方法使邪气随汗液排出而解除。
如果有不从太阳经传变，而是传入少阳经的情况，经典中说：“伤寒病，脉象弦细，出现头痛、发热的，属于少阳病。少阳病禁止使用发汗法。”如果误治导致病情涉及胃腑，胃气调和则病愈，胃气不和则会出现心烦和心悸。因为“弦”脉是少阳病的定型脉象，其头痛特别像是邪气向外溢出到太阳经，而不是太阳经本身的自发病。所以张仲景特别强调禁止发汗。另外，如果是太阳病与少阳病同时存在（并病），出现头项强痛，或者头晕目眩，有时感觉像结胸证一样，心下部痞塞硬满的，千万不可发汗，也不可攻下。既然汗法和下法都不可用，就应采用和解少阳的方法。虽然张仲景没有明说具体方药，但医者应根据证候灵活领会运用。
阳明病尤其忌讳发汗。经典中说：“伤寒六七天，不大便，头痛且有发热的，给予承气汤治疗。”但如果小便清长的，知道病邪不在里，仍在表，这时应当需要发汗。如果此时头痛剧烈，可能会导致鼻出血（衄血）。这句话的意思是，风寒之邪由表入里，但热邪尚未完全入里，仍然适宜用汗法解表；如果热邪已经入里，则应该用承气汤来泻下。由此推断，湿热之邪本在于体内，但向外溢于体表，在初起时常常见到头痛证候，治疗应当以清利里热为主，微微兼用透表之法。如果里气调和，表证自然解除。如果单纯使用攻表的方法，不仅头痛不能减轻，恐怕还会使里证加重。
太阴病也有出现头痛的情况。经典中说：“霍乱病，出现头痛、发热、身体疼痛，如果热多想喝水的，用五苓散治疗；如果寒多不想喝水的，用理中汤治疗。”霍乱属于太阴病证。头痛发热，说明阴病有转化为阳证的转机，只有迅速去除体内的寒邪，病邪转出到阳分，才可以治愈。
少阴一经，与太阳经互为表里。太阳经的脉象浮，少阴经的脉象沉。经典中说：“病人发热、头痛，脉象反而沉，如果服药后未痊愈，身体疼痛的，宜用四逆汤治疗。”因为沉脉不是太阳病的脉象，就不能按照太阳病发表的原则，给予大发汗的治疗了。
太阴经和少阴经的经脉上行至颈胸部即返回，不循行于头部，按理说不应有头痛证候。然而阴阳之气出入运行，互相输注呼应，其机理妙在转化，不能死板固执地论述。至于厥阴经的经脉，循行喉咙后方，向上进入颃颡（鼻咽部），连接眼睛深处，向上出于额部，与督脉会合于头顶。厥阴病也有头痛的情况，如经典所说：“干呕、吐涎沫、头痛的，用吴茱萸汤治疗。”这就是厥阴头痛的例子。厥阴头痛往往直冲巅顶，如果疼痛剧烈连及脑部，并且手足寒冷的，属于不治之症。
太阳经的病如果不解，转传入腑，病人会出现头痛且小便不利，治疗应当不从经表解，而从腑里解。如经典所说：“服用桂枝汤，或者经过攻下治疗后，仍然头项强痛，微热，无汗，心下部胀满微痛，小便不利的，用桂枝去桂加茯苓白术汤治疗。”这是为了运化胸中的阳气，以化解寒水之气，使邪气从小便排出而解除，所以说“小便利则病愈”。由此推断，如果有热邪结聚在腑，出现头痛、小便不利，再加上口渴的症状，则适宜用甘寒的药物泻除腑热，头痛自然自愈。这种方法也可以融会贯通运用。
太阳经的邪气聚集在上部，就会出现头项强痛；聚集在下部，就会出现项背强痛。经典中说：“太阳病，项背部僵硬拘急（KT KT 指拘急不舒之状），反而出汗、怕风的，用桂枝加葛根汤治疗。”“太阳病，项背部僵硬拘急，无汗、怕风的，用葛根汤治疗。”这是通过有汗和无汗来区分风寒与发热同义的证候。又经典中说：“病人身体发热，脚冷，颈项强直紧急，怕冷，有时头部发热、面色发红，眼脉络赤红，只有头面部摇动，突然牙关紧闭、角弓反张的，这是痉病，另详痉病门。”还有结胸证，项部也僵硬，类似柔痉的状态，攻下后就会缓和，宜用大陷胸丸。这是因为气结于胸中，牵连项部导致僵硬，所以攻下后气机通畅就会缓和。这虽然出现了项强的证候，但其邪气并不关乎太阳经。
(Attached: Stiffness of the Neck and Occiput)
The principal manifestation of Taiyang disease (Disease of the Taiyang Channel) is a floating pulse, stiffness and pain in the head and neck, and aversion to cold. This indicates that stiffness and pain in the head and neck are specific to Taiyang syndromes. However, such symptoms may also occasionally appear in diseases of other channels, though they are most characteristic of Taiyang. Whenever pathogenic factors enter from the exterior, headache is invariably present. As stated in the classics: "In Taiyang disease, with headache, fever, body ache, lower back pain, joint pain, aversion to wind, absence of sweating, and wheezing, Mahuang Tang (Ephedra Decoction) should be administered." "In Taiyang disease, with headache, fever, sweating, and aversion to wind, Guizhi Tang (Cinnamon Twig Decoction) should be administered." These conditions share the same mechanism as fever; Wind-Cold pathogens entering from the exterior manifest with a floating pulse, thus allowing for resolution through diaphoresis (sweating) to expel the pathogen.
If the disease does not originate in Taiyang but involves Shaoyang (Lesser Yang), the classics state: "In Cold Damage, if the pulse is wiry and fine, accompanied by headache and fever, it belongs to Shaoyang. Shaoyang disease prohibits diaphoresis." If mismanagement leads to involvement of the Stomach, harmony of the Stomach results in recovery, while disharmony causes irritability and palpitations. The wiry pulse is definitive for Shaoyang; the headache here is specifically due to pathogenic overflow into the Taiyang channel rather than a primary Taiyang pathology. Therefore, Zhang Zhongjing explicitly forbids diaphoresis. Furthermore, in concurrent Taiyang and Shaoyang disease, presenting with stiffness and pain in the head and neck, dizziness, or sensations resembling Chest Binding (Jie Xiong) with epigastric fullness and hardness, one must strictly avoid both diaphoresis and purgation. Since neither method is applicable, the approach should be harmonizing the Shaoyang. Although Zhang Zhongjing did not specify formulas here, physicians should adapt based on clinical presentation.
Yangming disease particularly contraindicates diaphoresis. The classics state: "After six or seven days of Cold Damage, if there is constipation, headache, and fever, Chengqi Tang (Gastro-Regulating Decoction) should be given." However, if urination is clear, it indicates the pathogen is not in the interior but remains in the exterior, requiring diaphoresis. If headache is severe at this stage, nasal bleeding (epistaxis) may occur. This implies that when Wind-Cold enters from the exterior but heat has not fully penetrated the interior, diaphoresis is appropriate; once heat enters the interior, purgation with Chengqi Tang is indicated. By inference, Damp-Heat pathogens reside primarily in the interior but overflow to the exterior; early stages often present with headache. Treatment should focus on clearing interior heat while gently releasing the exterior. Once interior harmony is restored, the exterior resolves spontaneously. Solely attacking the exterior will not relieve the headache and may exacerbate interior symptoms.
Taiyin disease can also present with headache. The classics state: "In Huoluan (Colic-Restriction Disease), with headache, fever, and body pain: if heat predominates and thirst for water is desired, Wuling San (Five-Ingredient Powder with Poria) is indicated; if cold predominates and there is no desire for water, Lizhong Tang (Regulate the Middle Decoction) is indicated." Huoluan is a Taiyin syndrome. Headache and fever indicate a potential transformation from Yin to Yang. Rapid elimination of interior cold allows the pathogen to exit via the Yang level, rendering the condition treatable.
Shaoyin (Lesser Yin) stands in interior-exterior relationship with Taiyang. The Taiyang pulse is floating, whereas the Shaoyin pulse is deep. The classics state: "If a patient presents with fever, headache, and a paradoxically deep pulse, and symptoms persist despite treatment, accompanied by body pain, Sini Tang (Frigid Extremities Decoction) is appropriate." A deep pulse is not characteristic of Taiyang; therefore, one cannot apply the standard exterior-releasing protocol of massive diaphoresis used for Taiyang.
Taiyin and Shaoyin channels ascend to the neck and chest and return, not traversing the head; theoretically, they should not present with headache. However, the dynamic of Yin-Yang qi circulation and mutual correspondence involves subtle transformations, precluding rigid dogmatic interpretation. The Jueyin (Terminal Yin) channel, however, ascends behind the throat, enters the nasopharynx, connects to the eyes, emerges above the forehead, and meets the Du Vessel at the vertex. Jueyin disease can cause headache, as stated: "Dry vomiting, spitting saliva, and headache are treated with Wuzhuyu Tang (Evodia Decoction)." Jueyin headaches often ascend directly to the vertex. If pain is severe, radiating to the brain, accompanied by cold extremities, it is considered incurable.
If Taiyang channel disease fails to resolve and transmits to the Bladder Fu organ, the patient presents with headache and dysuria. Treatment should target the Fu organ rather than the channel. For instance: "After administering Guizhi Tang or undergoing purgation, if stiffness and pain in the head and neck persist, along with slight fever, absence of sweating, epigastric fullness and mild pain, and dysuria, Guizhi Qu Gui Jia Fuling Baizhu Tang (Cinnamon Twig Decoction without Cinnamon plus Poria and Atractylodes Macrocephala Decoction) is indicated." This formula promotes Yang qi in the chest to transform Cold-Water accumulation, facilitating excretion via urination. Hence, "when urination becomes free, the disease resolves." By extension, if Heat binds in the Fu organ causing headache, dysuria, and thirst, sweet-cold herbs should be used to drain Fu heat, resolving the headache. This principle can be applied flexibly.
When Taiyang pathogen accumulates superiorly, it causes stiffness and pain in the head and neck; when it accumulates inferiorly, it causes stiffness in the nape and back. The classics state: "In Taiyang disease, if the nape and back are stiff and uncomfortable, with sweating and aversion to wind, Guizhi Jia Gegen Tang (Cinnamon Twig Decoction plus Kudzu Root) is indicated. If the nape and back are stiff and uncomfortable, with no sweating and aversion to wind, Gegen Tang (Kudzu Root Decoction) is indicated." Differentiation between sweating and non-sweating distinguishes Wind-Cold patterns sharing fever mechanisms. Additionally: "If a patient has body heat, cold feet, stiff and urgent neck, aversion to cold, intermittent facial heat and redness, red eye vessels, isolated head tremor, sudden lockjaw, and opisthotonos, this is Jing Disease (Spasm Disease), detailed elsewhere." In Chest Binding, the neck may also be stiff, resembling flexible spasm; purgation brings relief, using Da Xianxiong Wan (Major Trap the Chest Pill). This occurs because Qi binding in the chest pulls the neck stiff; purgation releases this tension. Although neck stiffness appears, the pathogen does not primarily involve the Taiyang channel.