或曰。伤寒内伤瘴疟之不同。已知之矣。敢问瘴与疟。何以辨之。予曰有三阳经疟。三阴经疟。
五脏疟。又有以寒多热少者。及单寒者。名寒疟。寒热相半者。名温疟。单热不寒者。名单疟。
胸膈痰痞心下胀满气逆烦呕为痰疟。噫气吞酸胸腹胀吐酸恶酸恶食为食疟。恶风自汗筋骨痛抽搐为风疟。
面垢口渴心烦多汗为暑疟。三日一发。久而不愈为 疟。表里俱虚。客邪未散。真气不复。间一日连二日发。
或疾虽间。遇劳即发。久而不瘥为劳疟。进退无时。进则神昏。退则如常为鬼疟。久而不瘳。膈下
结块为疟母。发于阳者为牡疟。发于
阴者为牝疟。虽种种不同。其大略不外于一日一发。或二日一发。三日一发。有间一日连二日发。
有一日两发。有日与夜各发。有上半日发。有下半日发。有有汗。有无汗。此一定之规。若瘴疟
只是三症。以有寒者为寒瘴。单热者为热瘴。不语者为哑瘴。其始发也。多不间断。重者七日方间
断。其间断也。一日十二时。只间一二时。即发亦有间断半日者。退去时。莫起动则可。若起动则
发。又终属难退。即退去。胸腹之热尚在。或间一日一发者。其发时去死一间。其退去之时。浑身上
下筋骨。若无其难过也。不可以言语形容。非若诸疟退去之时。即如平人。又或先轻后重。或先重后轻。
或先间断而后反不间断。或先不间断而后间断。变怪不常。非若诸疟作息自有定期。以此辨别。
皎若日星。其治诸疟。用药错者尚可救。疗瘴疟。用药一错。祸如反掌。瘴最忌者。汗吐下及小柴胡汤。
柴苓汤。解肌汤。其故何也。盖瘴因阳气外泄而然。发汗之药
多驱内阳外泄。是重虚其内。所以多死。瘴因阳气不降于下焦。吐则阳气愈上升。下元无阳气。
是无根也。故死。瘴疾是下真寒而上假热。下药太寒。一下咽则中寒大作。阳气随之即脱。所以死极速。
瘴病外虽热而内实寒。故人谓瘴疾为脾寒。正谓瘴也。故小柴胡柴苓解肌之类。其性俱大寒。服
之则外热不降。而内寒更甚。故至外热微时。里外俱无阳气。所以难救。欲治斯病。医者自首至尾。
不同妄用一药。只遵大法。温中镇下。正气相解。且攻且守。主病者无责速效。病者能慎疾。则治自愈。
万不失一矣。若夫哑瘴。当归之天命。千百中可救一二。非人力之所能为也。
有人问：伤寒、内伤与瘴疟的不同，我已经知道了。冒昧请问，瘴疾与疟疾，如何辨别呢？我说：有属于三阳经的疟疾，有属于三阴经的疟疾，有五脏疟。又有寒多热少的，以及只有寒冷没有发热的，称为寒疟；寒热各半的，称为温疟；只有发热没有寒冷的，称为单疟。胸膈间痰湿阻滞、心下胀满、气逆烦闷呕吐的，称为痰疟；嗳气吞酸、胸腹胀痛、吐酸水、厌恶酸味、食欲不振的，称为食疟；怕风、自汗、筋骨疼痛、抽搐的，称为风疟；面色垢浊、口渴、心烦、多汗的，称为暑疟。每隔三天发作一次，日久不愈的，称为三日疟。表里俱虚，外邪未散，真气不能恢复，隔一天连第二天一起发作的，或者虽然间隔发作，但遇到劳累就发作，日久不痊愈的，称为劳疟。发作时间没有规律，发作时神志昏迷，退去时如常人一样的，称为鬼疟。日久不愈，膈下出现结块的，称为疟母。发于阳分的称为牡疟，发于阴分的称为牝疟。虽然种类种种不同，其大致规律不外乎一日一发，或二日一发，或三日一发；有的隔一天连第二天发作；有的是一天发作两次；有的是白天和夜晚各发作一次；有的是上半日发作，有的是下半日发作；有的有汗，有的无汗。这是有一定规律的。至于瘴疟，只有三种症状：伴有寒冷的称为寒瘴；只有发热的称为热瘴；不语（失语）的称为哑瘴。瘴疟刚开始发作时，大多不间断，重症者要七天才能间断。其间断的时间，一天十二个时辰中，只间断一两个时辰，即又发作；也有间断半日的。在退去的时候，不要起身活动就可以；如果起身活动就会再次发作，而且终究难以退去。即使退去了，胸腹间的余热仍在。有的隔一天发作一次，其发作时距死亡仅差一步之遥；其退去的时候，浑身上下筋骨，痛苦得无法用言语形容。不像其他疟疾退去时，就像正常人一样。或者病情先轻后重，或先重后轻，或先有间断而后反而不间断，或先不间断而后出现间断，变化怪异无常，不像其他疟疾发作和停止自有定期。以此辨别，清楚得像日月星辰一样。治疗各种疟疾，用药错误还有可能挽救；治疗瘴疟，用药一旦错误，灾祸如反掌之间般迅速发生。瘴疾最忌讳的是发汗、催吐、泻下法以及小柴胡汤、柴苓汤、解肌汤。这是什么原因呢？大概瘴疾是因为阳气外泄而导致的。发汗的药物大多驱使内部阳气向外泄露，这是使内部更加虚弱，所以大多导致死亡。瘴疾是因为阳气不能下降至下焦，催吐则使阳气更加上升，下元没有阳气，这就是无根之阳，所以死亡。瘴疾是下焦真寒而上焦假热，使用泻下药过于寒凉，一下咽下去则中焦寒邪大作，阳气随之立即脱失，所以死亡极其迅速。瘴病外表虽然发热，但内部实际上是寒证，所以人们称瘴疾为脾寒，正是指瘴疾而言。因此小柴胡汤、柴苓汤、解肌汤这类药物，性质都大寒，服用它们则外部热象不能下降，而内部寒邪更甚，所以到了外部热象轻微时，内外都没有阳气了，所以难以救治。想要治疗这种病，医生从开始到结束，不要胡乱使用一种药物，只遵循大法，温补中焦，镇摄下焦，调和正气，且攻且守，主治疾病的医生不追求速效，病人能谨慎对待疾病，那么病自然痊愈，万无一失了。至于哑瘴，只能听天命，千百人中可救一二，不是人力所能做到的。
A question was raised: "The differences between Shanghan (Cold Damage), Neishang (Internal Injury), and Zhangmalaria are now understood. I dare to ask, how can one distinguish Zhangji (Miasma Disease) from Nuemalaria?" I replied: "There are Nuemalaria affecting the Three Yang meridians, Nuemalaria affecting the Three Yin meridians, and Zang-Fu Nuemalaria. Furthermore, there is Hanmalaria (Cold Malaria), characterized by more cold than heat or only cold without heat; Wenmalaria (Warm Malaria), characterized by equal amounts of cold and heat; and Danmalaria (Simple Fever Malaria), characterized by fever alone without chills. Tanmalaria (Phlegm Malaria) presents with phlegm obstruction in the chest and diaphragm, fullness below the heart, rebellious Qi, irritability, and vomiting. Shimalaria (Food Stagnation Malaria) presents with belching, acid regurgitation, abdominal distension and pain, vomiting of sour fluid, aversion to sour taste, and poor appetite. Fengmalaria (Wind Malaria) presents with aversion to wind, spontaneous sweating, bone and joint pain, and convulsions. Shumalaria (Summerheat Malaria) presents with a greasy complexion, thirst, irritability, and excessive sweating. Sanrimie (Three-Day Malaria) occurs every three days and persists for a long time without resolution. Biaoli Juxu (Deficiency of both Exterior and Interior) with lingering pathogenic factors and unrecovered True Qi, manifesting as attacks on consecutive days after an interval, or attacks triggered by exertion despite intervals, persisting for a long time without recovery, is called Laomalaria (Labor Malaria). Guiemie (Ghost Malaria) has no fixed timing; during attacks, there is coma, while between attacks, the patient appears normal. Jiunbu Chou (Chronic Non-resolution) with masses forming below the diaphragm is called Numu (Malaria Mother). Those arising from the Yang aspect are called Mumie (Male Malaria); those arising from the Yin aspect are called Pinmie (Female Malaria). Although various types differ, their general patterns do not exceed once daily, once every two days, or once every three days; some occur on consecutive days after an interval; some occur twice a day; some occur once during the day and once at night; some occur in the first half of the day, others in the second half; some present with sweating, others without. This is a fixed rule. As for Zhangmalaria (Miasma Malaria), it manifests in only three symptoms: accompanied by cold is called Hanzhang (Cold Miasma); fever alone is called Rezhang (Heat Miasma); muteness is called Yazhang (Mute Miasma). At onset, Zhangmalaria often continues without interruption; severe cases may only interrupt after seven days. During interruptions, within the twelve double-hours of a day, the interruption lasts only one or two hours before recurring; some interruptions last half a day. When the symptoms recede, if the patient remains still, it is manageable; if they move, the attack recurs and is difficult to subside. Even when subsided, residual heat remains in the chest and abdomen. Some occur every other day; during attacks, death seems imminent; during subsidence, the pain throughout the bones and joints is indescribable, unlike other malarias where patients return to normal upon subsidence. The course may vary: mild then severe, severe then mild, intermittent then continuous, or continuous then intermittent. These changes are irregular, unlike other malarias which have regular cycles. Distinguishing them is as clear as the sun and stars. For treating various malarias, medication errors can sometimes be corrected and saved; but for Zhangmalaria, a single medication error leads to disaster instantly. Zhangmalaria strictly contraindicates sweating, emesis, purgation, Xiao Chai Hu Tang (Minor Bupleurum Decoction), Chai Ling Tang (Bupleurum and Poria Decoction), and Jieji Tang (Muscle-Relieving Decoction). Why? Zhangmalaria arises from the leakage of Yang Qi outward. Sweating agents drive internal Yang further outward, exacerbating internal deficiency, leading to frequent death. Zhangmalaria involves Yang Qi failing to descend to the Lower Jiao; emesis causes Yang to rise further, leaving the Lower Yuan devoid of Yang (rootless Yang), leading to death. Zhangmalaria features true cold in the lower part and false heat in the upper part; harsh purgatives are too cold; upon ingestion, Middle Jiao cold flares up, causing immediate Yang collapse and rapid death. Zhang disease appears hot externally but is cold internally, hence called 'Spleen Cold.' Therefore, formulas like Xiao Chai Hu Tang, Chai Ling Tang, and Jieji Tang, being largely cold in nature, fail to resolve external heat and worsen internal cold. When external heat diminishes, Yang Qi is absent both inside and outside, making rescue difficult. To treat this disease, physicians must avoid arbitrary medication from start to finish, adhering only to the major principle: warm the Middle, anchor the Lower, harmonize Zheng Qi (Upright Qi), combining attack and defense. Physicians should not seek quick results, and patients must observe strict precautions; thus, recovery will naturally occur with high certainty. However, Yazhang (Mute Miasma) is subject to destiny; only one or two out of a thousand might be saved, beyond human capability."