燥，回阳，宣，通脉
生用辛温，逐寒邪而发表。炮则辛苦大热，除胃冷而守中（辛则散，炮则稍苦，故止而
不移，非若附子走而不守）。温经止血（炮黑止吐衄诸血，红见黑则止也），定呕消痰，去脏
腑沉寒痼冷。能去恶生新，使阳生阴长，故吐衄下血，有阴无阳者宜之。亦能引血药入气分
而生血，故血虚发热、产后大热者宜之（此非有余之热，乃阴虚生内热也，忌用表药寒药。
干姜能入肺，利气；能入肝，引血药生血，故与补阴药同用。乃热因热用，从治之法，故亦
治目睛久赤）。引以黑附，能入肾而祛寒湿，能回脉绝无阳（仲景四逆、白通、姜附汤，皆
用之）。同五味利肺气而治寒嗽（肺恶寒）。燥脾湿而补脾（脾恶湿），通心助阳而补心气（苦
入心），开五脏六腑，通四肢关节，宣诸脉络。治冷痹寒痞，反胃下利。多用损阴耗气，孕
妇忌之（辛热能动血。王好古曰∶服干姜以治中者必僭上，宜大枣辅之。东垣曰∶宜甘草以
缓之）。母姜晒干者为干姜，炮黑为黑姜。
古名薯蓣
补脾肺，涩精气
色白入肺，味甘归脾。入脾、肺二经，补其不足，清其虚热（阴不足则内热，补阴故能
清热）。固肠胃，润皮毛，化痰涎，止泻痢（渗湿故化痰止泻。《百一方》∶山药半生半炒，
米饮下。治噤口痢）。肺为肾母，故又益肾强阴，治虚损劳伤（王履云∶八味丸用之以强阴）
；脾为心子，故又益心气（子能令母实），治健忘遗精（昂按∶山药性涩，故治遗精泄泻，
而诸家俱未言涩）。生捣，敷痈疮，消肿硬（山药能消热肿，益补其气，则邪滞自行。丹溪
云∶补阳气生者，能消肿硬是也）。色白而坚者入药。
【干姜】
味辛性燥，具有回阳救逆、宣通血脉的功效。
生用：气味辛温，能驱逐寒邪并发散表邪。
炮制后：气味变为辛苦且大热，能消除胃中寒冷并固守中焦（辛味能发散，炮制后略带苦味，因此作用止而不走，不像附子那样走窜而不固守）。
功效包括：温经止血（炮黑后可止住吐血、衄血等各种出血，因为“红见黑则止”），平定呕吐、消除痰饮，去除脏腑深处的沉寒痼冷。
它能去除恶浊之气而生成新气，使阳气生长从而促进阴血化生，所以对于吐血、衄血、便血等只有阴液亏损而无阳气固摄的病症适宜使用。
它也能引导补血药进入气分从而促进生血，所以对于血虚发热、产后大热的病症适宜使用（这种热不是实热有余，而是阴虚产生的内热，忌用解表药和寒凉药。干姜能入肺经，利顺肺气；能入肝经，引导血药生血，所以与补阴药同用。这是“热因热用”的从治法，所以也能治疗眼睛长期发红）。
若以黑附子为引，能入肾经而祛除寒湿，能挽回脉绝无阳的危象（如张仲景的四逆汤、白通汤、姜附汤，都使用了它）。
与五味子同用，能利肺气而治疗寒性咳嗽（肺脏厌恶寒冷）。
燥脾湿而补脾气（脾脏厌恶湿气），通心阳而补心气（苦味入心），开通五脏六腑，通达四肢关节，宣通各种脉络。
治疗冷痹、寒痞、反胃、下利。
但多用会损伤阴液、耗散正气，孕妇忌用（辛热之性容易动血。王好古说：服用干姜治疗中焦病证必然会导致气机上僭，宜用大枣辅助。李东垣说：宜用甘草来缓和其烈性）。
母姜晒干者称为干姜，炮黑者称为黑姜。
【山药】
古称薯蓣。
功效：补益脾肺，固涩精气。
颜色白色入肺经，味道甘美归脾经。
入脾、肺二经，补充其不足，清除虚热（阴液不足则产生内热，补阴故能清热）。
固护肠胃，滋润皮毛，化痰涎，止泻痢（通过渗湿作用化痰止泻。《百一方》记载：山药一半生用一半炒用，米汤送服。治疗噤口痢）。
肺为肾之母，所以又能益肾强阴，治疗虚损劳伤（王履说：八味丸中使用山药来强健阴气）；脾为心之子，所以又能益心气（子能令母实），治疗健忘、遗精（汪昂按语：山药性质涩滞，所以治疗遗精泄泻，但各家医家都没有提到它的涩性）。
生捣碎，外敷痈疮，消肿硬（山药能消除热肿，补益正气，则邪气停滞自然自行消散。朱丹溪说：补阳气而生长的山药，能消除肿硬）。
选择颜色白且质地坚硬的入药。
[Shengyong] (Raw use): Pungent and warm, it drives out cold pathogens and releases the exterior.
[Paozhi] (Processed): Becomes pungent, bitter, and greatly hot; it eliminates stomach cold and stabilizes the middle jiao (Pungency disperses, but processing adds slight bitterness, so its action is stationary rather than moving, unlike Fuzi which moves without stabilizing).
It warms the meridians and stops bleeding (processed to blackness, it stops hematemesis, epistaxis, and various other bleedings, as "red stops when seeing black"); it calms vomiting, resolves phlegm, and removes deep-seated cold from the zang-fu organs.
It can eliminate evil and generate newness, allowing Yang to grow and Yin to lengthen; therefore, it is suitable for conditions of hematemesis, epistaxis, and lower body bleeding where there is Yin deficiency without Yang consolidation.
It can also guide blood-tonifying herbs into the Qi level to generate blood; thus, it is suitable for fever due to blood deficiency or high fever after childbirth (this is not excess heat, but internal heat generated by Yin deficiency; superficial-releasing and cold-natured drugs are contraindicated. Ganjiang enters the Lung meridian to benefit Qi flow; it enters the Liver meridian to guide blood herbs in generating blood, so it is used with Yin-tonifying herbs. This is the treatment method of "treating heat with heat" (reversal treatment), so it also treats chronic redness of the eyes).
Guided by Heifuzi (Black Prepared Aconite Root), it enters the Kidney meridian to dispel cold-dampness and restores Yang in cases of pulselessness and absence of Yang (e.g., Sini Tang, Baitong Tang, Jiangfu Tang by Zhang Zhongjing all use it).
Combined with Wuweizi, it benefits Lung Qi and treats cold coughs (the Lung dislikes cold).
It dries Spleen dampness and tonifies Spleen Qi (the Spleen dislikes dampness); it unblocks Heart Yang and tonifies Heart Qi (Bitter enters the Heart); it opens the five zang and six fu organs, unblocks the joints of the four limbs, and circulates the collaterals.
It treats cold bi syndrome, cold痞 (fullness), regurgitation, and diarrhea.
However, excessive use damages Yin and consumes Qi; pregnant women should avoid it (Pungent and hot nature can move blood. Wang Haogu stated: Taking Ganjiang to treat the middle jiao inevitably causes Qi to rebel upwards, so it should be assisted by Dazao. Li Dongyuan stated: It should be moderated with Gancao).
The mother ginger dried in the sun is called Ganjiang; processed to blackness is called Heijiang.
[Yam]
Ancient name: Shuyu.
Benefits the Spleen and Lung, astringes Essence and Qi.
Its white color enters the Lung; its sweet taste returns to the Spleen.
Entering the Spleen and Lung meridians, it tonifies deficiencies and clears deficient heat (Yin deficiency leads to internal heat; tonifying Yin thus clears heat).
It consolidates the intestines and stomach, moistens skin and hair, transforms phlegm-saliva, and stops diarrhea and dysentery (by promoting diuresis to transform phlegm and stop diarrhea. *Baiyi Fang*: Yam, half raw and half stir-fried, taken with rice drink. Treats Jin Kou Li [dysentery with inability to eat]).
The Lung is the mother of the Kidney, so it also tonifies the Kidney and strengthens Yin, treating deficiency damage and consumptive disease (Wang Lu stated: In Bawei Wan, Yam is used to strengthen Yin); the Spleen is the child of the Heart, so it also benefits Heart Qi (the child makes the mother full), treating forgetfulness and seminal emission (Wang Ang notes: Yam's nature is astringent, hence it treats seminal emission and diarrhea, though previous authors did not mention its astringency).
Crushed raw and applied externally to carbuncles and sores, it reduces swelling and hardness (Yam can reduce heat-swelling; by tonifying Qi, pathogenic stagnation dissipates naturally. Zhu Danxi stated: Yam that tonifies Yang Qi and generates tissue can reduce swelling and hardness).
Those that are white in color and firm in texture are used for medicine.