《内经·疟论》云∶ 疟皆生于风，而发作有时何也。岐伯曰∶夏伤于暑，秋必病疟。
谓腠理开而汗出遇风，或得于澡浴，水气舍于皮肤，因卫气不守，邪气并居，其疾始作。
伸欠寒栗，腰背俱痛，骨节烦疼，寒去则内外皆热，头疼而渴。乃阴阳二气交争，虚实
更作而然。阴气独胜则阳虚，故先寒战栗，腰背头项骨节皆痛。阳气独胜则阴虚，故先热，
发时不嗜食，善呕头疼腰痛，小便不利，阴盛阳虚，则内外皆寒。阳盛阴虚，则内外俱
热，此外感六淫，或内伤七情，蕴积痰饮，病气与卫气并居，故病日作。卫气昼行于阳，夜
行于阴，得阳而外出，得阴而内薄，内薄五脏，六气深入，不能与卫气俱出，则间日而
作，当卫气所至，病气所在，则发。在阳则热，在阴则寒，经曰∶亢则害，极乃反。俟
阴阳各衰，卫气与病气相离则病休。阴阳相搏，卫气与病气再集则病复。各随其卫气之
所在，与所中邪气相合而然也。先寒后热者，先伤寒而后伤风，名曰寒疟。先热后寒者，先
伤风而后伤寒，名曰温疟。但热不寒者名曰瘅疟，身重寒热，骨节痛，腹胀满，自汗
善呕，名曰湿疟。但寒不热者。名曰牝疟。盖疟之为病，而证状非一。故处方之制，随其
阴阳虚实，脉病证治，汗吐下温，对证施剂，以平为期。然百病中人，必因其正气之虚，感
受邪气，留而不去，其病为实，自表传里，先汗后下，古今不易。盖治疟之法，必须先表，
用百解散，水姜、葱煎投，次小柴胡汤，加桂，水、姜、枣煎服，以和解表里之邪，自
然作效。若表里实，用当归散、五和汤，或乌犀丸、六圣丸下之，匀气散止补，后以藿
香饮加草果、良姜，水、姜、枣煎投，正胃气，去寒邪，则自平复。如解表后，寒热往
来，以二仙饮或三圣丸截之。寒热既除，用平胃散加茴香汤和匀，盐汤空心调服。温胃
燥脾，进饮食，使中州之土既实，则外邪不战而自屈，此为明论。有寒多热少经久不愈，
致脾胃弱，饮食减，神色慢，二姜丸主之，及清脾汤为治。每见治疟不明理者，多取草药
挪水冷服，或露而投之，水伤脾胃，耗损真元，变证百出，或传成浮肿，或转作疳泻，或
变为冷痢，致脾胃虚弱，饮食减少，因而不救者有之。且婴孩娇脆，何堪用以草药服饵？
为医为父母者，切宜戒之。
《黄帝内经·疟论》中说：疟疾都是由风邪引起的，为什么发作有固定的时间呢？岐伯回答说：夏天被暑邪所伤，到了秋天必定会患疟疾。
这是因为腠理（皮肤毛孔）张开时出汗，遇到风邪，或者在洗澡沐浴时，水气停留在皮肤之间，因为卫气不能固守，邪气趁机占据身体，疾病才开始发作。
出现打哈欠、怕冷颤抖，腰部和背部都疼痛，骨节烦扰疼痛，寒气消退后体内体外都发热，头痛且口渴。这是阴阳二气相互争斗，虚实交替变化所致。如果阴气单独占优势则阳气虚弱，所以先出现寒战颤抖，腰部、背部、头部、颈部和骨节都疼痛。如果阳气单独占优势则阴气虚弱，所以先出现发热，发病时不想吃东西，容易呕吐，头痛腰痛，小便不通利。如果阴盛阳虚，则体内体外都寒冷。如果阳盛阴虚，则体内体外都发热。这些是外感六淫（风、寒、暑、湿、燥、火），或内伤七情（喜、怒、忧、思、悲、恐、惊），蕴积痰饮，病气与卫气共同停留，所以疾病每天发作。卫气白天行走在阳分，夜晚行走在阴分，遇到阳分就外出体表，遇到阴分就向内迫近五脏，六气深入，不能随卫气一起外出，就会隔日发作，当卫气运行到病气所在之处，疾病就会发作。在阳分则发热，在阴分则发冷，经书说：亢盛就会造成危害，极点就会反转。等到阴阳之气各自衰退，卫气与病气分离，疾病就会休止。阴阳相互搏结，卫气与病气再次聚集，疾病就会复发。这都是随着卫气所在的位置，与所中的邪气相合而形成的。
先冷后热的，是先感受寒邪而后感受风邪，名叫寒疟。先热后冷的，是先感受风邪而后感受寒邪，名叫温疟。只有发热没有寒冷的，名叫瘅疟（dàn nüè）。身体沉重、忽冷忽热、骨节疼痛、腹部胀满、自汗、容易呕吐的，名叫湿疟。只有寒冷没有发热的，名叫牝疟（pìn nüè）。大概疟疾这种病，症状表现不止一种。所以处方的制定，要随着其阴阳虚实、脉象病症的治疗原则，采用汗法、吐法、下法、温法等，对症用药，以平衡为准则。然而百病侵入人体，必定是因为正气虚弱，感受了邪气，留滞不去，病势转为实证，由表传里，先用汗法后用下法，古今不变。
大概治疗疟疾的方法，必须先解表，使用百解散，用水、生姜、葱白煎煮服用；其次用小柴胡汤，加入桂枝，用水、生姜、大枣煎服，以和解表里的邪气，自然见效。如果表里俱实，使用当归散、五和汤，或者乌犀丸、六圣丸攻下；用匀气散止呕补虚，随后用藿香饮加草果、良姜，用水、生姜、大枣煎煮服用，以正胃气，去除寒邪，则自然平复。如果解表之后，仍有寒热往来，用二仙饮或三圣丸截断病势。寒热既已消除，用平胃散加茴香汤调和均匀，盐汤空腹调服。温胃燥脾，促进饮食，使中焦脾胃之气充实，则外邪不战而自屈，这是明理之论。如果有寒多热少、经久不愈，导致脾胃虚弱，饮食减少，神色倦怠，用二姜丸主治，以及清脾汤来治疗。
我常看见治疗疟疾不明白医理的人，多取草药捣碎后用冷水送服，或者露天放置后投药，这样会损伤脾胃，耗损真元，变证百出，有的发展成浮肿，有的转变成疳泻，有的变为冷痢，导致脾胃虚弱，饮食减少，因而无法救治的情况也有。况且婴幼儿娇嫩脆弱，怎么能承受用草药服用呢？作为医生和父母，务必以此为戒。
The *Neijing · Malaria Chapter* states: "All malaria arises from wind, yet why does it occur at specific times?" Qibo replied: "Summer injury by summer-heat leads to malaria in autumn."
This is because when the couli (skin pores) are open and sweating occurs, exposure to wind, or obtaining water qi during bathing which lodges in the skin, combined with the failure of Wei Qi (Defensive Qi) to guard, allows pathogenic factors to occupy the body, causing the disease to begin.
Manifestations include yawning, chills, pain in the waist and back, vexing pain in bone joints. After the cold subsides, both interior and exterior become hot, accompanied by headache and thirst. This results from the contention between Yin and Yang Qi, alternating deficiency and excess. When Yin Qi alone prevails, Yang becomes deficient; thus, chills and tremors occur first, with pain in the waist, back, head, neck, and joints. When Yang Qi alone prevails, Yin becomes deficient; thus, heat appears first. During attacks, there is loss of appetite, propensity to vomit, headache, lower back pain, and difficult urination. If Yin is excessive and Yang deficient, both interior and exterior are cold. If Yang is excessive and Yin deficient, both interior and exterior are hot. These conditions stem from external contraction of the Six Excesses (Wind, Cold, Summer-Heat, Dampness, Dryness, Fire), or internal injury from the Seven Emotions (Joy, Anger, Worry, Pensiveness, Sorrow, Fear, Fright), leading to accumulation of phlegm-fluids. Pathogenic Qi and Wei Qi coexist, causing daily recurrence. Wei Qi travels through the Yang aspect during the day and the Yin aspect at night; encountering Yang, it moves outward to the surface; encountering Yin, it presses inward toward the five zang organs. When the six qi penetrate deeply and cannot exit with Wei Qi, the disease manifests every other day. When Wei Qi reaches the location of the pathogen, the disease flares up. In the Yang aspect, there is heat; in the Yin aspect, there is cold. The classics state: "Exuberance causes harm; extremity reverses." When Yin and Yang Qi decline separately, and Wei Qi separates from Pathogenic Qi, the disease rests. When Yin and Yang contend again, and Wei Qi gathers with Pathogenic Qi, the disease recurs. This depends on the location of Wei Qi combining with the contracted pathogen.
Cold preceding heat indicates injury by Cold followed by Wind, named Cold Malaria. Heat preceding cold indicates injury by Wind followed by Cold, named Warm Malaria. Heat without cold is named Dan Malaria (Febrile Malaria). Heavy body, alternating cold and heat, joint pain, abdominal distension, spontaneous sweating, and vomiting characterize Damp Malaria. Cold without heat is named Pin Malaria (Yin Malaria). Generally, malaria presents with various symptoms. Therefore, prescription formulation must follow Yin-Yang, deficiency-excess, pulse-disease patterns, employing diaphoresis, emesis, purgation, or warming methods, matching symptoms to balance the body. All diseases invade due to righteous Qi deficiency, allowing pathogens to linger and transform into excess, moving from exterior to interior, utilizing diaphoresis then purgation, an unchanging principle since antiquity.
Treating malaria requires first resolving the exterior using Baijie San (Hundred-Resolution Powder) decocted with water, ginger, and scallion. Next, use Xiaochaihu Tang (Minor Bupleurum Decoction) with added Guizhi (Cinnamon Twig), decocted with water, ginger, and jujube, to harmonize and resolve exterior-interior pathogens, naturally yielding effects. If exterior and interior are both excess, use Danggui San (Angelica Powder), Wuhe Tang (Five-Harmony Decoction), Wuxi Wan (Black Rhinoceros Pill), or Liusheng Wan (Six-Sages Pill) for purgation. Use Yunqi San (Qi-Balancing Powder) to stop vomiting and tonify; subsequently use Huoxiang Yin (Agastache Drink) with Caoguo (Tsaoko Fruit) and Liangjiang (Galangal), decocted with water, ginger, and jujube, to rectify Stomach Qi and dispel cold, restoring balance. If after resolving the exterior, alternating cold and heat persist, use Erxian Yin (Two-Immortals Drink) or Sansheng Wan (Three-Sages Pill) to intercept the attack. Once cold and heat are eliminated, use Pingwei San (Stomach-Calming Powder) with Huixiang (Fennel) decoction, mixed evenly, taken with salt water on an empty stomach. This warms the stomach, dries the spleen, promotes appetite, and strengthens the Middle Jiao Earth, causing external pathogens to yield without struggle, a sound theoretical approach. For cases with much cold and little heat persisting long-term, leading to weak spleen-stomach, reduced diet, and lethargy, treat with Erjiang Wan (Two-Ginger Pills) and Qingpi Tang (Clear Spleen Decoction).
I often observe practitioners treating malaria without understanding principles, resorting to herbal remedies crushed and taken with cold water, or exposed to dew before administration. This damages the spleen-stomach, depletes true Yuan Qi, and generates myriad complications: edema, kan diarrhea (infantile malnutrition with diarrhea), or cold dysentery, leading to spleen-stomach weakness, reduced intake, and sometimes death. Infants are delicate and fragile; how can they endure such herbal ingestion? Physicians and parents must strictly beware of this.