大凡头痛属三阳，乃邪气上攻也。太阳专主头痛，阳明、少阳亦有之。三阴络上不过头，惟厥
阴循喉咙之后，上连目，系顶巅，故有头痛干呕，吐涎沫之证，却无身热，亦与阳证不同。虽然，
风湿在少阴，湿温在太阴，其经从足走至胸中而还，及头痛过于阴毒，是又不可拘也。若两感于寒，
太阳、少阴俱病，则头痛口干，烦
满而渴，与夫头痛极甚，又连于胸，手足寒者，则为真头痛，不可治矣。
太阳病，头痛发热，恶寒无汗，麻黄汤；有汗，桂枝汤。已发汗，未发汗，头痛如破者，葛根
葱白汤。太阳病，下之，脉细数者，头痛未止，连须葱白汤。
阳明头痛，不恶寒反恶热，六七日不大便，胃实，气攻于上也，少与调胃承气汤。少阳头痛，
脉弦，发热，小柴胡汤。
湿家头痛，鼻塞，瓜蒂末纳鼻中，黄水出立愈。痰涎头痛，胸满寒热，脉紧，瓜蒂散吐之。
厥阴头痛，干呕吐涎沫，吴茱萸汤。头痛，壮热心烦，栀子黄芩汤。天行、劳复头痛，四肢痛，
葱头汤。
项背强者，太阳表邪也，发散则解。结胸项强，有下之证。寒湿项强，则成 ，见本条，临病
宜审。
太阳病，项强，无汗恶风，为表实，葛根汤；项背强，发热，汗出恶风，为表虚，桂枝加葛根。
误下太阴，结胸，项强，大陷胸丸。一法频与理中丸。若损甚者，兼与四逆汤。
项强，胁下满，身热恶风，手足温而渴，小柴胡汤。
阴毒，初得病，项背强，咽痛，心腹痛，短气，厥逆吐利，身如被杖，附子汤、阴毒甘草汤、
正阳汤。天明复作热，至晚则腰痛，头项强，身重，葛根生姜豉汤。
Generally, headache belongs to the Three Yang meridians, caused by pathogenic factors attacking upwards. The Taiyang meridian specifically governs headache, while the Yangming and Shaoyang meridians also present with it. The collaterals of the Three Yin meridians do not ascend beyond the head; only the Jueyin meridian circulates behind the throat, ascends to connect with the eyes, and attaches to the vertex. Therefore, symptoms such as headache, dry retching, and vomiting of saliva occur, but without fever, which differs from Yang syndromes. Nevertheless, wind-dampness in the Shaoyin meridian and damp-warmth in the Taiyin meridian follow pathways from the foot to the chest and then return. Furthermore, headaches severe enough to resemble Yin toxicity cannot be rigidly confined to these rules. If affected by cold simultaneously (Taiyang and Shaoyin both diseased), symptoms include headache, dry mouth, irritability, fullness, and thirst. If the headache is extremely severe, radiating to the chest, accompanied by cold hands and feet, it is termed "True Headache" (Zhen Tou Tong) and is incurable.
For Taiyang disease presenting with headache, fever, aversion to cold, and anhidrosis, use Mahuang Tang (Ephedra Decoction); if there is sweating, use Guizhi Tang (Cinnamon Twig Decoction). Regardless of whether diaphoresis has already been induced or not, if the headache is excruciating as if the head were splitting, use Gegen Congbai Tang (Kudzu and Scallion White Decoction). For Taiyang disease where purgation was mistakenly applied, resulting in a fine and rapid pulse with persistent headache, use Lianxu Congbai Tang (Scallion White with Roots Decoction).
Yangming headache presents with no aversion to cold but rather aversion to heat, constipation for six or seven days, stomach excess, and qi attacking upwards; administer a small dose of Tiaowei Chengqi Tang (Regulate the Stomach and Order the Qi Decoction). Shaoyang headache presents with a wiry pulse and fever; treat with Xiaochaihu Tang (Minor Bupleurum Decoction).
In patients with dampness suffering from headache and nasal congestion, insert powder of Gengdi (Seed of Melon) into the nose; yellow fluid discharge leads to immediate cure. For headache caused by phlegm-fluid retention, accompanied by chest fullness, alternating chills and fever, and a tight pulse, induce vomiting using Gengdi San (Gengdi Powder).
Jueyin headache characterized by dry retching and vomiting of saliva is treated with Wuzhuyu Tang (Evodia Decoction). Headache with high fever and irritability is treated with Zhizi Huangqin Tang (Gardenia and Scutellaria Decoction). Headache due to epidemic pathogens or relapse after exertion, accompanied by limb pain, is treated with Congtou Tang (Scallion Head Decoction).
Stiffness of the neck and back is due to exterior pathogenic factors of the Taiyang meridian; resolving the exterior will alleviate it. Neck stiffness associated with Chest Binding (Jie Xiong) indicates indications for purgation. Neck stiffness due to cold-dampness leads to specific manifestations (refer to the relevant section); clinical judgment is required.
For Taiyang disease with neck stiffness, anhidrosis, and aversion to wind, indicating Exterior Excess, use Gegen Tang (Kudzu Decoction). For neck stiffness with fever, sweating, and aversion to wind, indicating Exterior Deficiency, use Guizhi Jia Gegen Tang (Cinnamon Twig Decoction plus Kudzu). If mistaken purgation leads to Taiyang disease complicated by Chest Binding and neck stiffness, use Daxiexion Wan (Major Xiexion Pill). Alternatively, frequently administer Lizhong Wan (Regulate the Middle Pill). If damage is severe, combine with Sini Tang (Frigid Extremities Decoction).
Neck stiffness with hypochondriac fullness, fever, aversion to wind, warm hands and feet, and thirst is treated with Xiaochaihu Tang (Minor Bupleurum Decoction).
Yin Toxicity initially presents with neck stiffness, sore throat, heart and abdominal pain, shortness of breath, cold extremities, vomiting and diarrhea, and body pain resembling being beaten with a stick; treat with Fuzi Tang (Aconite Decoction), Yindu Gancao Tang (Yin Toxicity Licorice Decoction), or Zhengyang Tang (Upright Yang Decoction). If fever recurs at dawn, followed by night-time lower back pain, neck stiffness, and heaviness of the body, use Gegen Shengjiang Chi Tang (Kudzu, Ginger, and Fermented Soybean Decoction).