【气味】
辛温无毒。体轻而上行。浮而升阳也。入足太阳经。（即取木桂之最薄者。去其粗
皮是也。）
【主治】
伤风头痛。开腠理。解表止烦发汗。去皮肤风湿。泄奔豚。散下焦蓄血。利肺气。
疗痛风。横行手臂。或曰本草言桂枝能止烦出汗。故张仲景治伤寒有当发汗之症。凡数处皆
用桂枝汤。此与本草之义甚相符合。又云无汗不得用桂枝。汗家不得重发汗。则桂枝又所禁
用。而仲景伤寒有汗多之症。凡数处每用桂枝甘草汤。此又似用桂枝以闭汗也。其说何以辨
之。盖太阳中风。阴弱而汗自出。此为卫实荣虚。故发热汗出也。又太阳病非中风。而发热
汗出者。此为荣弱卫强。而阴虚阳必凑之也。皆用桂枝汤以发其汗。乃调其荣气。则卫气自
和。风邪无所容。遂自汗而解。非桂枝能开腠理发出其汗也。然则桂枝汤下发汗之发字。当
认作出字。汗自然发出。非若麻黄症。必以麻黄开发腠理而出其汗也。则凡仲景之用桂枝汤
以发汗者。其症必皮肤疏泄。自汗脉浮缓。风邪干于卫气者。为对症之剂。其汗多而用桂枝
甘草汤者。盖腠理不密。则津液外泄。而肺气自虚。虚则当补其母。用桂枝同甘草。外散风
邪以救表。内伐肝木以防脾。佐以芍药。泄土中之木而固脾。使以姜枣以通行脾之津液。如
是而荣卫无不调和矣。荣卫既和。则邪从汗出。而汗自止。非桂枝能闭汗孔也。明乎此。而
仲景之治伤寒有汗。用桂枝不令重发其汗者。是解肌之妙用也。若太阳中风。腠理致密。荣
卫邪实。津液禁固。其脉浮紧。发热而汗不出者。则属麻黄症。不可以桂枝为能发散解肌利
关节而误用之也。
【气味】
辛、温，无毒。药性轻清且向上运行。具有浮散升阳的作用。归入足太阳膀胱经。（即选取木桂中最薄的部分，并去除其粗糙的外皮。）
【主治】
治疗伤风引起的头痛。开通腠理（皮肤毛孔及纹理），解除表邪，缓解烦躁，发汗。祛除皮肤中的风湿之邪。平抑奔豚气（一种气从少腹上冲胸咽的病症）。消散下焦蓄积的血瘀。通利肺气。治疗痛风。药力横行于手臂部位。
有人说，本草著作中说桂枝能止烦、出汗，所以张仲景在治疗伤寒出现需要发汗的症状时，多处都使用了桂枝汤。这与本草的理论非常相符。又说，无汗者不得使用桂枝，平时多汗的人不得再次强力发汗，那么桂枝又是被禁止使用的。然而张仲景在《伤寒论》中遇到汗多的症状时，多处每用桂枝甘草汤。这看起来又像是使用桂枝来收敛止汗。这两种说法该如何辨别呢？
大概是因为太阳中风证，阴液虚弱而汗自出，这是卫气实而营气虚，所以发热且汗出。另外，太阳病并非中风，但也出现发热汗出的，这是因为营弱卫强，阴虚则阳气必凑集于体表。这些情况都用桂枝汤来发汗，其实是调和营气，那么卫气自然和谐，风邪无处容身，于是通过自然出汗而病解。这并不是桂枝能强行开通腠理发出汗液。既然这样，那么桂枝汤方剂中“发汗”的“发”字，应当理解为“出”，即汗液自然排出，不像麻黄证那样，必须依靠麻黄开发腠理才能排出汗液。因此，凡是张仲景使用桂枝汤来发汗的情况，其症状必定是皮肤疏泄、自汗、脉象浮缓，属于风邪侵犯卫气的病症，桂枝汤是对症的方剂。
至于那些汗多而使用桂枝甘草汤的情况，是因为腠理不紧密，导致津液外泄，从而肺气自然虚弱。虚证当补其母脏（土生金，脾为肺之母；或根据上下文语境，此处指通过调理脾胃以益肺气，或指肝木克脾土，需兼顾），使用桂枝配合甘草，向外疏散风邪以救表，向内伐除肝木以防其过度克制脾土。佐以芍药，泄去脾土中郁滞的木气以固护脾脏。使以生姜、大枣以通行脾脏的津液。像这样，营卫之气没有不调和的。营卫既已调和，那么邪气随汗而出，汗自然停止。这并不是桂枝能关闭汗孔。明白了这一点，就知道张仲景治疗伤寒有汗症，使用桂枝而不令其再次强力发汗，这是解除肌表邪气的妙用。如果是太阳中风，但腠理致密，营卫邪气盛实，津液被禁锢，脉象浮紧，发热且不出汗的，则属于麻黄汤证，不可以因为桂枝能发散、解肌、利关节而误用它。
[Flavor and Nature]
Acrid, warm, non-toxic. The substance is light in nature and ascends. It floats and raises Yang. It enters the Foot-Taiyang Bladder Meridian. (This refers to selecting the thinnest bark of Cinnamomi Ramulus [Guizhi], removing its rough outer layer.)
[Indications]
Treats headache caused by wind-cold injury. Opens the Cou-li (interstices/skin pores), releases the exterior, relieves irritability, induces sweating. Expels wind-dampness from the skin. Subdues Ben-tun (a condition characterized by gas rushing upward from the lower abdomen). Disperses blood stasis accumulated in the Lower Jiao. Promotes Lung Qi. Treats Bi syndrome (painful obstruction) affecting the arms; its action extends horizontally through the arms.
Some state that Materia Medica texts say Cinnamomi Ramulus can relieve irritability and induce sweating. Therefore, Zhang Zhongjing used Guizhi Tang (Cinnamon Twig Decoction) in multiple instances when treating Shanghan (Cold Damage) with symptoms requiring sweating. This aligns well with the principles of Materia Medica. However, it is also stated that Cinnamoli Ramulus should not be used for patients without sweat, and those who are prone to sweating should not undergo heavy sweating therapy again; thus, Cinnamoli Ramulus seems contraindicated. Yet, in Shanghan Lun, Zhang Zhongjing frequently uses Guizhi Gancao Tang (Cinnamon Twig and Licorice Decoction) for conditions with excessive sweating. This appears to suggest using Cinnamoli Ramulus to stop sweating. How can these statements be reconciled?
Generally, in Taiyang Wind-Strike syndrome, Yin is weak, leading to spontaneous sweating. This represents Excess Wei (Defensive Qi) and Deficiency Ying (Nutritive Qi), resulting in fever and sweating. In other cases of Taiyang disease, though not Wind-Strike, if there is fever and sweating, it indicates Ying weakness and Wei excess, where Yin deficiency allows Yang to encroach upon the surface. In all such cases, Guizhi Tang is used to induce sweating. However, this actually harmonizes Ying Qi, causing Wei Qi to become balanced naturally. Once harmonized, the wind pathogen has no place to reside, and the disease resolves through natural sweating. This is not because Cinnamoli Ramulus forcibly opens the Cou-li to expel sweat. Therefore, the character "Fa" (release/induce) in "Fa Han" (induce sweating) within Guizhi Tang should be understood as "Chu" (exit/emerge); the sweat emerges naturally, unlike in Mahuang syndrome, where Ephedrae Herba is required to open the Cou-li to force out sweat. Thus, whenever Zhang Zhongjing uses Guizhi Tang to induce sweating, the patient's symptoms must include porous skin, spontaneous sweating, and a floating-slow pulse, indicating wind pathogen invading Wei Qi. Guizhi Tang is the appropriate formula for these indications.
Regarding the use of Guizhi Gancao Tang for excessive sweating: when the Cou-li are not tight, body fluids leak outward, leading to inherent deficiency of Lung Qi. For deficiency patterns, one should tonify the mother organ (Spleen Earth generates Lung Metal, or addressing Liver Wood overacting on Spleen Earth). Cinnamoli Ramulus combined with Glycyrrhizae Radix et Rhizoma (Licorice Root) disperses wind pathogen externally to rescue the exterior and subdues Liver Wood internally to prevent it from overwhelming Spleen Earth. Paeoniae Radix Alba (White Peony Root) is added as an assistant to drain stagnant Wood from Spleen Earth and secure the Spleen. Zingiberis Rhizoma Recens (Fresh Ginger) and Jujubae Fructus (Jujube) are used as guides to promote the circulation of Spleen fluids. Through this method, Ying and Wei Qi are harmonized. Once Ying and Wei are harmonized, pathogens exit via sweat, and sweating stops naturally. This is not because Cinnamoli Ramulus closes the sweat pores. Understanding this clarifies that when Zhang Zhongjing treats Shanghan with sweating using Cinnamoli Ramulus, he does so not to induce heavy sweating, but to skillfully release the muscle layer (Jie Ji). If, however, it is Taiyang Wind-Strike with tight Cou-li, excess pathogens in Ying and Wei, imprisoned body fluids, a floating-tight pulse, fever, and absence of sweating, this belongs to Mahuang Tang syndrome. One must not mistakenly use Cinnamoli Ramulus simply because it can disperse, release the muscle layer, and benefit joints.