治热伤元气，气短倦怠，口干出汗。
人参 麦门冬 五味子
上三味，用水煎服。
柯韵伯曰∶肺为娇脏，而朝百脉，主一身元气者也。形寒饮冷则伤肺，故伤寒有脉结
代，与脉微欲绝之危。暑热刑金则伤肺，故伤热有脉来虚散之足虑。然伤寒是从外来者为
实邪，故虽脉不至而可复可通。伤热是从所不胜来者为贼邪，非先从滋化其源，挽回于未绝之前，则一绝而不可
复。此孙真人为之急培元气，而以生脉名方也。麦门冬甘寒，清权衡治节之司，人参甘温，补后天营卫之本，五
味酸温，收先天天癸之原，三气通而三才立，水升火降，而合既济之理矣。仲景治伤寒，有通脉复脉二法。少阴
病里寒外热，下利清谷，脉微欲绝者，制通脉四逆汤，温补以扶阳。厥阴病外寒内热，心动悸，脉结代者，制复
脉汤，凉补以滋阴。同是伤寒，同是脉病，而寒热异治者，一挽坎阳之外亡，一清相火之内炽也。生脉散本复脉立
法，外无寒故不用姜桂之辛散，热伤无形之气，未伤有形之血，故不用地黄、阿胶、麻仁、大枣，且不令其泥膈而
滞脉道也。心主脉而苦缓，急食酸以收之，故去甘草而加五味矣。脉资始于肾，资生于胃，而会于肺，仲景二
方，重任甘草者，全赖中焦谷气以通之复之，非有待于生也，此欲得下焦天癸之元气以生之，故不藉甘草之缓，必取
资于五味之酸矣。
治疗热邪损伤元气，出现气短、疲倦乏力、口干、出汗的症状。
人参 麦门冬 五味子
以上三味药，用水煎煮后服用。
柯韵伯说：肺是娇嫩的脏器，朝会百脉，主管一身元气。形体受寒或饮食生冷就会损伤肺，所以伤寒病会出现脉结代（脉搏跳动不规则，时有中止）和脉微欲绝（脉搏微弱，似乎要断绝）的危重情况。暑热之邪克制肺金就会损伤肺，所以伤热病会出现脉来虚散（脉搏虚弱散乱）的值得忧虑的情况。然而，伤寒是从外部侵入的实邪，所以即使脉搏暂时摸不到，也可以恢复和通畅。伤热是从“所不胜”（即克我者，此处指火克金，暑热属火，肺属金）而来的贼邪，如果不先从根源滋助化源，在元气未完全断绝之前挽回，那么一旦断绝就无法恢复。这就是孙真人急于培补元气，并将此方命名为生脉的原因。麦门冬味甘性寒，清肃主持权衡治节的脏腑功能；人参味甘性温，补益后天营卫的根本；五味子味酸性温，收敛先天天癸的源头。三气相通而天、地、人三才确立，水升火降，符合既济（水火相交，阴阳平衡）的道理。张仲景治疗伤寒，有通脉和复脉两种方法。少阴病里寒外热，下利完谷不化，脉微欲绝的，制作通脉四逆汤，用温补的方法来扶助阳气。厥阴病外寒内热，心动悸，脉结代的，制作复脉汤，用凉补的方法来滋阴。同样是伤寒，同样是脉象病变，但寒热治疗方法不同，是因为一个挽救坎阳的外亡，一个清除相火的内炽。生脉散本于复脉汤的立法原则，因为外无寒邪，所以不用生姜、桂枝的辛散；热邪损伤的是无形之气，没有损伤有形的血，所以不用地黄、阿胶、麻仁、大枣，也不让它们黏腻膈膜而阻滞脉道。心主脉且苦缓，急需食用酸味药来收敛它，所以去掉甘草而加入五味子。脉气起源于肾，滋养来源于胃，汇聚于肺，张仲景的两个方剂，重用甘草，是完全依赖中焦谷气来通达和恢复脉象，并非有待于生成新的元气，这里想要得到下焦天癸的元气来生养脉象，所以不借助甘草的缓和之性，必须取用五味子的酸收之性。
Treats heat damaging the primordial qi, presenting with shortness of breath, fatigue, dry mouth, and sweating.
Ren Shen (Ginseng Radix), Mai Men Dong (Ophiopogonis Tuber), Wu Wei Zi (Schisandrae Fructus).
The above three herbs are decocted in water and taken orally.
Ke Yunbo stated: The Lung is a delicate organ that receives all vessels and governs the primordial qi of the entire body. Cold affecting the form or cold drinks injuring the interior will damage the Lung; thus, in Shanghan (Cold Damage), there are critical conditions such as Jie Dai Mai (Knotted and Intermittent Pulse) and Wei Yu Jue Mai (Faint Pulse on the verge of disappearance). Summerheat punishing Metal (Lung) damages the Lung; thus, in Heat Injury, there is the concern of Xu San Mai (Deficient and Scattered Pulse). However, Shanghan involves real pathogens coming from outside, so even if the pulse is absent, it can be restored and unblocked. Heat injury involves treacherous pathogens coming from what one cannot overcome (i.e., Fire overcoming Metal); unless the source is first nourished to restore vitality before it completely vanishes, once severed, it cannot be recovered. This is why Sun Simiao urgently tonified the primordial qi and named this formula Sheng Mai San (Generate the Pulse Powder). Mai Men Dong is sweet and cold, clearing the functions of weighing and regulating; Ren Shen is sweet and warm, tonifying the root of acquired Ying and Wei (Nutritive and Defensive Qi); Wu Wei Zi is sour and warm, gathering the origin of innate Tian Gui (Heavenly Water/Reproductive Essence). When the three energies connect, Heaven, Earth, and Humanity are established; Water ascends and Fire descends, fulfilling the principle of Ji Ji (Water-Fire Intersection/Balance). Zhang Zhongjing treated Shanghan with two methods: Tong Mai (Unblocking the Pulse) and Fu Mai (Restoring the Pulse). In Shaoyin disease with interior cold and exterior heat, diarrhea with undigested food, and faint pulse on the verge of disappearance, he formulated Tong Mai Si Ni Tang (Pulse-Rescuing Four Reversals Decoction) to warm and tonify to support Yang. In Jueyin disease with exterior cold and interior heat, palpitations, and knotted/intermittent pulse, he formulated Fu Mai Tang (Pulse-Restoring Decoction) to cool and tonify to nourish Yin. Although both are Shanghan and involve pulse pathology, the treatments for cold and heat differ because one rescues the external loss of Kan Yang (Kidney Yang) and the other clears the internal blazing of Xiang Huo (Ministerial Fire). Sheng Mai San is based on the legislation of Fu Mai Tang. Since there is no exterior cold, pungent dispersants like Sheng Jiang (Fresh Ginger) and Gui Zhi (Cinnamon Twig) are not used. Since heat damages formless Qi but has not damaged formless Blood, Di Huang (Rehmanniae Radix), E Jiao (Donkey-Hide Gelatin), Ma Ren (Semen Cannabis), and Da Zao (Jujubae Fructus) are not used, nor are they allowed to clog the diaphragm and obstruct the pulse channels. The Heart governs the pulse and dislikes slackness; therefore, sour substances are urgently consumed to astringe it. Thus, Gan Cao (Licorice Root) is removed and Wu Wei Zi is added. Pulse qi originates in the Kidney, is nourished by the Stomach, and converges in the Lung. In Zhang Zhongjing's two formulas, Gan Cao is heavily used because it relies entirely on Middle Jiao Grain Qi to unblock and restore the pulse, not depending on generation. Here, the intention is to obtain the primordial Qi of the Lower Jiao Tian Gui to generate it; therefore, the moderating nature of Gan Cao is not relied upon, but the astringent nature of Wu Wei Zi is essential.