?乃少阳部分，伤寒传至少阳，则?痛之病现矣。然有表里水气而?痛者，有邪热攻注而?痛者，
有食积相连而?痛者，有积痰咳喘而?痛者，有恶血停蓄而?痛者之不同。
项强
项强者，颈硬而不能回顾左右者也。盖太阳感受风寒，则经脉不利，而项为之急，巠为之强耳。是则
伤寒颈项强急，乃太阳表症也，发散则解。若结胸项强，误下之症。寒湿项强，则多痉症。一云、太阳病，
项背强几几，反汗出恶风者，桂枝加葛根汤主之。太阳病，项背强几几，无汗恶寒者，葛根汤主之。二
者均是项背强急，而发散则有轻重之不同。以发热汗出恶风为表虚，可解肌。无汗恶寒为表实，可
发汗。是以治之不同也。
有眩运者，有眩冒者，运为转运之运，此为头斿者是也，冒为蒙冒之冒，此为昏迷者是也，乃少阳为
病。以少阳属木，木能生风，风主运动，故时目斿而头眩也。针经曰、上虚则眩，下虚则厥。则知是少阳
表邪渐行于里，表中阳虚，故有此症也。然有太阳漏汗不止而头眩，有阳明风病善食而头眩，有汗
吐下后气虚而头眩，有素因怯弱血少而头眩，有火载痰上而头眩，有正气虚脱而头眩，有妇人经
水适来而头眩，有易病真元耗夺而眩运，轻则起方眩运，重则卧亦斿转矣。一云、不经汗吐下，脉眩
而眩运者，小柴胡汤主之。若经汗吐下后而眩运者，宜用温经之药，故仲景治头眩而用茯苓桂枝
白术甘草、真武之类。
侧头部疼痛属于少阳经循行部位，伤寒病邪传至少阳经时，就会出现侧头痛的病证。然而，导致侧头痛的原因各不相同：有的是因为表里水气停聚而致痛，有的是因为邪热攻冲注滞而致痛，有的是因为食积互结相连而致痛，有的是因为积痰引发咳喘而致痛，还有的是因为恶血（瘀血）停滞蓄积而致痛，这些情况各不相同。
项强
所谓项强，是指颈部僵硬，不能自如地左右回顾。大概是因为太阳经受受了风寒之邪，导致经脉运行不畅，从而使颈部变得紧急僵硬，经络拘急不舒。因此，伤寒引起的颈项强急，属于太阳经的表证，通过发散解表的方法即可解除。如果是结胸证出现的项强，那是误用下法导致的病症；寒湿引起的项强，则多伴有痉病（肌肉痉挛）。另一种说法认为：太阳病中，如果项背部僵硬拘急（几几，形容牵强不舒的样子），反而出现汗出、怕风的症状，应当用桂枝加葛根汤主治。太阳病中，如果项背部僵硬拘急，没有汗出且怕冷的症状，应当用葛根汤主治。这两种情况都是项背强急，但在发散解表方面有轻重程度的不同。以发热、汗出、怕风为表虚证，可以用解肌的方法治疗；以无汗、怕冷为表实证，可以用发汗的方法治疗。因此治疗方法有所不同。
有眩晕感的人，有头目昏蒙的人。“运”指的是转动，这里指头晕眼花；“冒”指的是蒙蔽，这里指神志昏迷，这属于少阳经的病证。因为少阳属木，木能生风，风主运动，所以会出现眼睛昏花、头晕的症状。《针经》说：上部虚则眩晕，下部虚则厥逆。由此可知，这是少阳表邪逐渐传入体内，导致体表阳气虚弱，所以出现这种症状。然而，也有太阳病漏汗不止而导致头晕的，有阳明风病食欲旺盛而导致头晕的，有经过发汗、催吐、泻下后气虚而导致头晕的，有素来体弱血少而导致头晕的，有火邪挟痰上扰而导致头晕的，有正气虚脱而导致头晕的，有妇女月经刚来潮而导致头晕的，有容易患病、真元耗损而导致眩晕的，轻则起身时感到眩晕，重则躺着也感觉天旋地转。另一种说法认为：如果没有经过发汗、催吐、泻下，脉象显示眩晕且感到头晕的，用小柴胡汤主治。如果经过发汗、催吐、泻下之后出现眩晕的，适宜使用温经的药物，所以张仲景治疗头晕时使用茯苓桂枝白术甘草汤、真武汤之类的方剂。
Pain in the lateral head region belongs to the Shaoyang channel area. When pathogenic cold from a Shanghan (Cold Damage) disease transmits to the Shaoyang channel, lateral headache manifests. However, the causes of lateral headache vary: some are due to water-dampness retention in the exterior and interior; some are due to attacking and stagnating pathogenic heat; some are due to interconnected food accumulation; some are due to accumulated phlegm causing cough and wheezing; and some are due to stasis blood (blood stasis) stagnation and accumulation. These conditions differ from one another.
Stiff Neck
"Stiff neck" refers to neck rigidity where one cannot look left or right freely. Generally, when the Taiyang channel is affected by wind-cold, the meridians become obstructed, causing the neck to become tight and rigid, and the channels to feel stiff. Thus, neck stiffness and rigidity caused by Shanghan belong to the exterior syndrome of the Taiyang channel and can be resolved through dispersing and releasing methods. If stiff neck occurs in Jie Xiong (Chest Binding), it is a condition resulting from erroneous purgation. Stiff neck caused by cold-dampness is often accompanied by Jing illness (spasm). Another view states: In Taiyang disease, if there is stiffness and tension in the nape and back (Ji Ji, describing a feeling of tightness and discomfort), accompanied by sweating and aversion to wind, Guizhi Jia Gegen Tang (Cinnamon Twig plus Kudzu Root Decoction) should be primarily used. In Taiyang disease, if there is stiffness and tension in the nape and back, without sweating and with aversion to cold, Gegen Tang (Kudzu Root Decoction) should be primarily used. Both cases involve stiffness and tension in the nape and back, but the dispersing and releasing treatments differ in intensity. Aversion to wind with fever and sweating indicates an Exterior Deficiency pattern, which can be treated by resolving the muscle layer. Absence of sweating with aversion to cold indicates an Exterior Excess pattern, which can be treated by inducing sweating. Therefore, the treatments differ.
Some experience Xuan Yun (vertigo/dizziness with a spinning sensation), while others experience Xuan Mao (dizziness with a sense of clouding or obscuration). "Yun" refers to rotation, indicating dizziness and blurred vision; "Mao" refers to obscuration, indicating confusion or coma. This belongs to Shaoyang disease. Since Shaoyang corresponds to Wood, and Wood generates Wind, and Wind governs movement, this results in blurred vision and dizziness. The Zhen Jing (Classic of Acupuncture) states: Deficiency in the upper part leads to vertigo; deficiency in the lower part leads to Jue (cold extremities/fainting). From this, we know that this is due to Shaoyang exterior pathogens gradually moving inward, causing deficiency of Yang Qi in the exterior, thus producing these symptoms. However, there are also cases of dizziness caused by incessant leakage of sweat in Taiyang disease; cases of dizziness associated with appetite increase in Yangming Wind disease; cases of dizziness following qi deficiency after sweating, vomiting, or purging; cases of dizziness in individuals constitutionally weak with blood deficiency; cases of dizziness caused by fire carrying phlegm upward; cases of dizziness due to collapse of righteous Qi; cases of dizziness occurring when a woman's menstruation has just begun; cases of vertigo due to depletion of True Yuan (Original Essence) in those prone to illness, where mild cases feel dizzy upon standing, and severe cases feel spinning even when lying down. Another view states: If there is no history of sweating, vomiting, or purging, and the pulse shows signs of vertigo with dizziness, Xiaochaihu Tang (Minor Bupleurum Decoction) should be primarily used. If vertigo occurs after sweating, vomiting, or purging, warming meridian herbs should be used. Therefore, Zhang Zhongjing treats dizziness using formulas such as Fuling Guizhi Baizhu Gancao Tang (Poria, Cinnamon Twig, Atractodes, and Licorice Decoction) and Zhenwu Tang (True Warrior Decoction).