麻黄∶味微苦，性温。为发汗之主药。于全身之脏腑经络，莫不透达，而又以逐发太阳风寒为其主治之
大纲。故《神农本草经》谓其主中风伤寒头痛诸证，又谓其主咳逆上气者，以其善搜肺风兼能泻肺定喘也。谓
其破 瘕积聚者，以其能透出皮肤毛孔之外，又能深入积痰凝血之中，而消坚化瘀之药可偕之以奏效也。且其
性善利小便，不但走太阳之经，兼能入太阳之府，更能由太阳而及于少阴（是以伤寒少阴病用之），并能治疮
疽白硬，阴毒结而不消。
太阳为周身之外廓，外廓者皮毛也，肺亦主之。风寒袭人，不但入太阳，必兼入手太阴肺经，恒有咳嗽
微喘之证。麻黄兼入手太阴为逐寒搜风之要药，是以能发太阳之汗者，不仅麻黄，而《伤寒论》治太阳伤寒无
汗，独用麻黄汤者，治足经而兼顾手经也。
凡利小便之药，其中空者多兼能发汗，木通、 蓄之类是也。发汗之药，其中空者多兼能利小便，麻黄、
柴胡之类是也。伤寒太阳经病，恒兼入太阳之腑（膀胱），致留连多日不解，麻黄治在经之邪，而在腑之邪亦
兼能治之。盖在经之邪由汗而解，而在腑之邪亦可由小便而解，彼后世用他药以代麻黄者，于此义盖未之审也。
受风水肿之证，《金匮》治以越婢汤，其方以麻黄为主，取其能祛风兼能利小便也。愚平素临证用其
方服药后果能得汗，其小便即顿能利下，而肿亦遂消。特是，其方因麻黄与石膏并用，石膏之力原足以监制
麻黄，恒有服之不得汗者，今变通其方，于
服越婢汤之前，先用白糖水送服西药阿斯匹林一瓦半，必能出汗，趁其正出汗时，将越婢汤服下，其汗出
必益多，小便亦遂通下。
东人××博士，用麻黄十瓦，煎成水一百瓦，为一日之量，分三次服下，治慢性肾炎小便不利及肾脏萎
缩小便不利，用之有效有不效，以其证之凉热虚实不同，不知用他药佐之以尽麻黄之长也。试观《金匮》水
气门越婢汤，麻黄辅以石膏，因其脉浮有热也（脉浮故系有风实亦有热），麻黄附子汤辅以附子，因其脉沉而
寒也。通变化裁，息息与病机相符，是真善用麻黄者矣。
古方中有麻黄，皆先将麻黄煮数沸吹去浮沫，然后纳他药，盖以其所浮之沫发性过烈，去之所以使其性
归和平也。
麻黄带节发汗之力稍弱，去节则发汗之力较强，今时用者大抵皆不去节，至其根则纯系止汗之品，本
是一物，而其根茎之性若是迥殊，非经细心实验，何以知之。
陆九芝谓∶“麻黄用数分，即可发汗，此以治南方之人则可，非所论于北方也。盖南方气暖，其人肌肤
薄弱，汗最易出，故南方有麻黄不过钱之语；北方若至塞外，气候寒冷，其人之肌肤强浓，若更为出外劳碌，
不避风霜之人，又当严寒之候，恒用七八钱始能汗者。夫用药之道，贵因时、因地、因人，活泼斟酌以胜病为
主，不可拘于成见也。”
麻黄：味道微苦，性质温。它是发汗的主要药物。它能通达全身脏腑经络，而其主治的大纲在于驱散太阳经的风寒。所以《神农本草经》说它主治中风、伤寒引起的头痛等各种证候，又说它主治咳嗽气逆，是因为它善于搜剔肺风兼能泻肺平喘。说它能破除癥瘕积聚，是因为它能透出皮肤毛孔之外，又能深入积痰凝血之中，配合消坚化瘀的药物可以奏效。而且它的性质善于通利小便，不仅走太阳经，还能进入太阳腑（膀胱），更能由太阳经波及少阴经（因此伤寒少阴病时使用它），并且能治疗疮疽白硬、阴毒凝结不消散的情况。
太阳经是周身的外廓，外廓即皮毛，肺也主皮毛。风寒侵袭人体，不仅进入太阳经，必定兼入手太阴肺经，常有咳嗽微喘的症状。麻黄兼入手太阴经，是驱寒搜风的要药，因此能发太阳经之汗的，不仅仅是麻黄，而《伤寒论》治疗太阳伤寒无汗，独用麻黄汤，是因为治疗足经的同时兼顾手经。
凡是通利小便的药物，其中空的多兼能发汗，如木通、萹蓄之类。凡是发汗的药物，其中空的多兼能通利小便，如麻黄、柴胡之类。伤寒太阳经病，常常兼入太阳之腑（膀胱），导致病程迁延多日不解，麻黄治疗在经之邪，而在腑之邪也能兼治。因为在经之邪通过发汗解除，而在腑之邪也可以通过小便解除，后世用其他药物代替麻黄的人，对此中的道理大概没有仔细审察。
患有风水肿证的，《金匮要略》用越婢汤治疗，该方以麻黄为主药，取它既能祛风又能利小便的作用。我平时临证使用此方，服药后如果能出汗，小便立即就能通利，肿胀也随之消退。只是这个方子因为麻黄与石膏并用，石膏的力量原本足以制约麻黄，常有服用后不出汗的情况。现在变通此方，在服用越婢汤之前，先用白糖水送服西药阿斯匹林一瓦半，必定能出汗，趁其正在出汗时，将越婢汤服下，其出汗必然更多，小便也随之通利。
日本人××博士，用麻黄十瓦，煎成水一百瓦，作为一天的量，分三次服用，治疗慢性肾炎小便不利及肾脏萎缩小便不利，有时有效有时无效，因为证候有凉热虚实不同，不知道用其他药物佐助以发挥麻黄的长处。试看《金匮要略》水气门中的越婢汤，麻黄辅以石膏，是因为脉浮且有热（脉浮故系有风，实亦有热）；麻黄附子汤辅以附子，是因为脉沉而寒。通变化裁，时刻与病机相符，这才是真正善于使用麻黄的人。
古方中有麻黄的，都是先将麻黄煮数沸，吹去浮沫，然后加入其他药物，大概是因为所浮起的沫子药性过于猛烈，去掉它为了使药性归于平和。
麻黄带节发汗之力稍弱，去节则发汗之力较强，如今使用时大多都不去节。至于麻黄根，则纯粹是止汗的药物，本是同一物，但其根茎的药性如此迥然不同，不是经过细心实验，怎么能知道呢？
陆九芝说：“麻黄用几钱就可以发汗，这用来治疗南方人可以，不适用于北方人。因为南方气候温暖，人的肌肤薄弱，汗最容易出，所以南方有‘麻黄不过钱’的说法；北方如果到了塞外，气候寒冷，人的肌肤强厚，如果再外出劳碌，不避风霜，又处于严寒之时，常常要用七八钱才能出汗。用药之道，贵在因时、因地、因人，灵活斟酌以战胜疾病为主，不可拘泥于成见。”
Mahuang (Ephedrae Herba): Taste slightly bitter, nature warm. It is the principal herb for inducing sweating. It penetrates and reaches all organs and meridians of the whole body, with its main therapeutic scope being the expulsion of Wind-Cold from the Taiyang (Greater Yang) channel. Therefore, *Shennong Bencao Jing* (Divine Farmer's Materia Medica) states that it treats headache and other syndromes caused by Wind-stroke and Cold damage, and also states that it treats cough and rebellious Qi, because it is good at searching out Lung Wind and can drain the Lung to calm wheezing. The statement that it breaks up masses and accumulations is because it can penetrate outside the skin pores and also deeply into accumulated phlegm and coagulated blood, allowing drugs that dissolve hardness and transform stasis to achieve efficacy alongside it. Moreover, its nature is good at promoting urination; it not only travels through the Taiyang channel but also enters the Taiyang fu-organ (Bladder), and can further extend from Taiyang to Shaoyin (Lesser Yin) (thus it is used in Shaoyin Cold Damage syndromes), and can treat white and hard carbuncles and ulcers, as well as Yin toxicity that knots and does not dissipate.
Taiyang serves as the outer covering of the body, which is the skin and hair, a function also governed by the Lung. When Wind-Cold invades the person, it not only enters the Taiyang channel but must also involve the Hand-Taiyin Lung channel, often resulting in symptoms of cough and slight wheezing. Mahuang involves the Hand-Taiyin channel and is an essential drug for expelling Cold and searching out Wind. Therefore, while herbs that induce sweating are not limited to Mahuang, *Shanghan Lun* (Treatise on Cold Damage) uses Mahuang Tang exclusively for Taiyang Cold Damage with no sweating, because it treats the Foot channels while taking care of the Hand channels.
Herbs that promote urination, those with hollow stems, often also induce sweating, such as Mutong (Akebiae Caulis) and Pianxi (Polygoni Avicularis Herba). Herbs that induce sweating, those with hollow stems, often also promote urination, such as Mahuang and Chaihu (Bupleuri Radix). In Taiyang channel diseases of Cold Damage, the pathogen often invades the Taiyang fu-organ (Bladder), causing lingering for many days without resolution. Mahuang treats the pathogen in the channel, and can also treat the pathogen in the fu-organ. This is because the pathogen in the channel is resolved through sweating, while the pathogen in the fu-organ can be resolved through urination. Those in later generations who use other drugs to replace Mahuang have likely not carefully examined this principle.
For syndromes of Wind-Water edema, *Jingui Yaolue* (Essential Prescriptions of the Golden Cabinet) treats them with Yuespi Tang (Dispersing the Spider Decoction), where Mahuang is the chief herb, utilizing its ability to dispel Wind and promote urination. In my usual clinical practice using this prescription, if the patient sweats after taking the medicine, urination immediately becomes smooth, and the swelling subsides. However, in this formula, Mahuang is used together with Shigao (Gypsum Fibrosum); the power of Gypsum is originally sufficient to restrain Mahuang, so there are cases where sweating does not occur after ingestion. Now, modifying this formula: before taking Yuespi Tang, administer 1.5 grains of Aspirin dissolved in white sugar water orally; this will surely induce sweating. While the patient is sweating, take Yuespi Tang; the sweating will increase significantly, and urination will subsequently flow smoothly.
Dr. XX from Japan used 10 grains of Mahuang, decocted in 100 grains of water, as a daily dose divided into three servings, to treat oliguria in chronic nephritis and oliguria due to renal atrophy. It was effective in some cases and ineffective in others, because the syndromes differed in cold/heat and deficiency/excess. He did not know how to use adjuvant herbs to fully utilize the strengths of Mahuang. Observe Yuespi Tang in the Water-Gas Chapter of *Jingui*: Mahuang is assisted by Shigao because the pulse is floating and heat is present (floating pulse indicates Wind, and there is indeed Heat). In Mahuang Fuzi Tang (Ephedra and Aconite Decoction), Mahuang is assisted by Fuzi (Aconiti Lateralis Radix Praeparata) because the pulse is deep and Cold is present. Through flexible modification, each change corresponds closely to the pathogenesis; this is truly someone who knows how to skillfully use Mahuang.
In ancient prescriptions containing Mahuang, Mahuang is first boiled for several boils, and the floating foam is blown away, then other herbs are added. This is presumably because the floating foam has overly fierce medicinal properties; removing it makes the nature of the herb peaceful.
Mahuang with nodes has a slightly weaker sweating-inducing power; removing the nodes makes the sweating-inducing power stronger. Currently, users mostly do not remove the nodes. As for Mahuang Gen (Ephedrae Radix et Rhizoma), it is purely a sweat-arresting agent. Although they come from the same plant, the properties of the root and stem are so vastly different. Without careful experimentation, how could one know this?
Lu Jiuzhi said: "Using a few qian of Mahuang can induce sweating; this applies to treating people in the South, but not those in the North. Because the climate in the South is warm, people's skin and muscles are thin, and sweat comes out most easily; hence the saying in the South that 'Mahuang should not exceed one qian.' In the North, especially beyond the Great Wall, the climate is cold, people's skin and muscles are thick and strong. If they also work outdoors laboriously, exposed to wind and frost, during severe cold weather, one often needs to use seven or eight qian to induce sweating. The way of using drugs values adapting to time, place, and individual, flexibly considering to overcome the disease as the primary goal, and should not be bound by preconceived notions."