《素问·刺疟篇》曰∶足太阳之疟，令人腰痛头重，寒从背起，先寒后热， 然，热止汗出，
难已，刺 中出血。
此下皆明足六经所行之现证也。足太阳经脉自足由背上头，故腰痛、头重、寒从背起，然风寒在太阳必
头痛，今不痛而但重者，正因湿邪所闭，阳郁不伸，故先背寒；其邪本在阳经，阳郁极则发热而 者，
遏闷不达也，故虽热止汗出，而病难已，为阴湿所闭也。郗中，太阳经穴，刺之以泄其邪。
足少阳之疟，令人身体解 ，寒不甚，热不甚，恶见人，见人心惕惕然，热多汗出甚，刺足少阳。
足少阳胆经之脉也，内通肝经，肝主筋，邪热侵之，筋脉弛纵而解 也；邪入近阴分，故发寒热而皆不甚；
其邪伤胆则胆
怯，故恶见人，见人而心惕然也；人身之阳，初由少阳而升，及其阳升邪发，则热多而汗出甚也。刺法同上。
足阳明之疟，令人先寒洒淅，洒淅寒甚，久乃热，热去汗出，喜见日月火光气，乃快然，刺足阳明跗上。
足阳明胃经之脉也，胃为脏腑之海而主肌肉，阳明行气于三阳，邪客之，三阳之气皆不伸，故先寒而洒淅
寒甚，久始发热；然后气行腠开，热去汗出，以邪未净则阳不能伸，故喜见日月火光为快也。
足太阴之疟，令人不乐，好太息，不嗜食，多寒热汗出，病至则善呕，呕已乃衰。
足太阴脾经之脉也，与心气相通，邪闭气不舒，故心不乐而好太息；脾困不运，故不嗜食；与阳明为表里，
其邪出入阴阳，表里相格，故多发寒热；而胃中水谷之气外泄，则汗出也；病至邪气冲胃，则善呕，呕已，邪
气乃衰也。
The *Suwen: Ci Nue Pian* (Chapter on Acupuncture for Malaria in the Plain Questions) states: In malaria of the Foot-Taiyang channel, the patient experiences lower back pain and a heavy sensation in the head; coldness arises from the back. There is initial chills followed by fever. The patient feels stifled and restless (*ran*). After the fever subsides, sweat is discharged, yet the disease is difficult to cure. Treatment involves pricking the Xi-Cleft point [Weizhong BL-40] to bleed.
The following sections clarify the manifest symptoms presented by the courses of the six Foot channels. The Foot-Taiyang channel meridian ascends from the foot along the back to the head; therefore, it causes lower back pain, heaviness of the head, and coldness arising from the back. Since wind-cold pathogen is in the Taiyang channel, headache is inevitable. The fact that there is no pain but only heaviness indicates that dampness pathogen is obstructing, causing Yang qi to be depressed and unable to extend. Hence, coldness is felt in the back first. As the pathogen resides in the Yang channel, extreme depression of Yang leads to fever and a feeling of stifled restlessness (*ran*), which signifies blocked and stagnant Qi mechanism. Thus, although sweat appears after the fever breaks, the disease remains difficult to resolve due to obstruction by Yin-dampness. Weizhong (BL-40) is an acupoint of the Taiyang channel; needling it drains the pathogenic factor.
In malaria of the Foot-Shaoyang channel, the patient’s body feels flaccid and weak (*jie gu*). The chills are not severe, nor is the fever severe. The patient dislikes seeing people and feels apprehensive and fearful upon seeing them. The fever is prominent with profuse sweating. Treatment involves needling the Foot-Shaoyang channel. The Foot-Shaoyang Gallbladder channel meridian connects internally with the Liver channel. The Liver governs the sinews. When evil heat invades, the sinews and vessels become lax, resulting in flaccidity. Because the pathogen enters near the Yin aspect, the chills and fever are both mild. The pathogen injures the Gallbladder, leading to timidity; thus, the patient dislikes social interaction and feels fearful when encountering others. Human Yang qi initially ascends via the Shaoyang channel. When Yang ascends and the pathogen erupts, fever becomes prominent with profuse sweating. The needling method is the same as above.
In malaria of the Foot-Yangming channel, the patient initially experiences shivering chills (*sa xi*), which are very severe. After a long time, fever develops. After the heat dissipates, sweat is discharged. The patient desires the presence of sunlight or moonlight/firelight, finding comfort in it. Treatment involves needling the acupoints on the dorsum of the foot of the Foot-Yangming channel. The Foot-Yangming Stomach channel meridian originates from the Stomach, which is the sea of the Zang-Fu organs and governs the muscles. Yangming distributes Qi among the three Yang channels. When the pathogen lodges there, the Qi of the three Yang channels cannot extend freely. Hence, there is initial chills with severe shivering, followed by fever after a delay. Subsequently, Qi moves, the interstices open, and sweat is discharged after the heat recedes. Because the pathogen is not yet cleared, Yang cannot extend; therefore, the patient finds relief in the presence of celestial light or fire.
In malaria of the Foot-Taiyin channel, the patient feels unhappy and frequently sighs deeply. There is loss of appetite. There are frequent alternating chills and fever with sweating. Upon the onset of the disease, vomiting occurs easily; the condition subsides after vomiting. The Foot-Taiyin Spleen channel meridian communicates with the Heart Qi. Pathogen obstruction causes Qi stagnation, leading to unhappiness and frequent deep sighs. Spleen dysfunction impairs transformation and transportation, resulting in poor appetite. The Spleen and Stomach are exterior-interior partners. The pathogen moves between Yin and Yang, creating mutual resistance between the interior and exterior, causing frequent alternating chills and fever. Leakage of the Qi of water and grain from the Stomach leads to sweating. When the disease strikes, the pathogenic Qi rushes against the Stomach, causing vomiting; after vomiting, the pathogenic Qi declines.