夫饮食劳役皆自汗，乃足阳明化燥火，津液不能停，故汗出小便数也。邪之大者，莫若
中风。风者，百病之长，善行而数变。虽然，无虚邪，则风雨寒不能独伤人，必先中虚邪，
然后贼邪得入矣。至于痿、厥逆，皆由汗出而得之也。且冬阳气伏藏于水土之下，如非常泄
精，阳气已竭，则春令从何而得，万化俱失所矣。在人则饮食劳役，汗下时出，诸病遂生。
予所以谆谆如此者，盖亦欲人知所慎也。
《黄帝针经》云∶寒热少气，血上下行。夫气虚不能寒，血虚不能热，血气俱虚，不能
寒热。而胃虚不能上行，则肺气无所养，故少气；卫气既虚，不能寒也。下行乘肾肝助火为
毒，则阴分气衰血亏，故寒热少气。血上下行者，足阳明胃之脉衰，则冲脉并阳明之脉，上
行于阳分，逆行七十二度，脉之火大旺，逆阳明脉中，血上行，其血冲满于上；若火时退伏
于下，则血下行，故言血上下行，俗谓之忽肥忽瘦者是也。经曰∶热伤气。又曰∶壮火食气
。故脾胃虚而火胜，则必少气，不能卫护皮毛，通贯上焦之气而短少也。阴分血亏，阳分气
削，阴阳之分，周身血气俱少，不能寒热，故言寒热也。《灵枢经》云∶上焦开发，宣五谷
味，熏肤充身泽毛，若雾露之溉，此则胃气平而上行也。
饮食不节和过度劳累都会导致自汗，这是因为足阳明胃经化生燥火，津液无法停留，所以出现出汗且小便频数的症状。在各类邪气中，没有比中风更严重的了。风邪是百病之长，善于游走变化且病情多变。虽然如此，如果没有正气虚弱的内在基础，风雨寒邪就不能单独伤人，必须先使人体内部虚弱，然后贼邪才能侵入。至于痿证、厥逆等病，都是由出汗后感受外邪而引发的。况且冬季阳气潜藏于水土之下，如果像经常泄精那样耗损阳气，导致阳气枯竭，那么春季的生发之气从何而来呢？万物化生都将失去依托。在人身上，饮食不节、过度劳累、频繁发汗或误用下法，各种疾病就会随之产生。我之所以反复谆谆告诫，正是希望人们知道要谨慎调养。
《黄帝针经》说：寒热往来、少气，血液上下妄行。气虚不能抵御寒冷，血虚不能抵御发热，气血俱虚，则既不能耐寒也不能耐热。如果胃气虚弱不能上行，肺气就得不到滋养，所以出现少气；卫气既然虚弱，就不能抵御寒冷。若虚火下行乘袭肾肝，助长火势成为毒邪，就会导致阴分气衰血亏，从而出现寒热、少气的症状。所谓“血上下行”，是因为足阳明胃脉衰弱，冲脉便并入阳明之脉，上行于阳分，逆行七十二度，脉中火气大旺，逆乱于阳明脉中，导致血液上行，充盈于上部；如果火气暂时退伏于下部，血液就会下行，所以说血液上下妄行，通俗称之为忽胖忽瘦的现象。经文说：热邪伤气。又说：壮火会消耗元气。所以脾胃虚弱而火邪亢盛时，必然导致少气，不能卫护皮毛，贯通上焦之气而显得短少。阴分血亏，阳分气削，阴阳两部分的周身气血都减少，既不能耐寒也不能耐热，所以说出现寒热症状。《灵枢经》说：上焦开发，宣发五谷的精微气味，熏蒸皮肤，充实身体，润泽毛发，就像雾露滋润一样，这是胃气平和而上行的表现。
Dietary irregularities and overexertion both lead to spontaneous sweating (Zihan, spontaneous sweating). This is because the Foot-Yangming Stomach Channel transforms into dryness-fire, preventing the retention of body fluids (Jinye, body fluids), thus causing sweating and frequent urination. Among all pathogenic factors, none is more severe than wind-stroke (Fengzhong, stroke caused by wind). Wind is the chief of a hundred diseases; it moves freely and changes frequently. Nevertheless, without deficiency-evil (Xuxie, pathogenic factors exploiting deficiency), wind, rain, cold, and heat cannot injure the body alone; internal deficiency must first be present before thief-evil (Zeixie, severe pathogens) can enter. Conditions such as flaccidity syndrome (Wei, atrophy syndrome) and reversal (Nijue, cold extremities with yang deficiency) are all contracted following sweating. Moreover, in winter, yang qi hides beneath water and earth. If one does not excessively discharge essence (as in frequent seminal emission), but instead exhausts yang qi, where will the springtime generating force come from? All transformations will lose their foundation. In humans, dietary irregularities, overexertion, frequent sweating, or improper use of purgatives cause various diseases to arise. I urge this repeatedly so that people may know how to exercise caution.
The *Huangdi Zhenjing* states: "Chills and fever, shortness of breath, and blood moving up and down." Qi deficiency cannot resist cold; blood deficiency cannot resist heat; if both qi and blood are deficient, neither cold nor heat can be resisted. When stomach qi is deficient and fails to ascend, lung qi lacks nourishment, resulting in shortness of breath (Shaoqi, insufficient breath); since defensive qi (Weiqi, defensive energy) is also deficient, it cannot resist cold. If fire descends to attack the Kidney and Liver, assisting fire to become toxic, yin qi declines and blood becomes deficient, leading to chills, fever, and shortness of breath. The phrase "blood moving up and down" refers to the decline of the Foot-Yangming Stomach Channel, causing the Chong Mai (Penetrating Vessel) to merge with the Yangming channel, ascending into the yang aspect, reversing through seventy-two cycles. Fire in the pulse becomes vigorous, rebelling within the Yangming channel, driving blood upward until it fills the upper body. If fire temporarily retreats downward, blood descends. Hence, "blood moving up and down," commonly known as fluctuating between obesity and emaciation (Hu Fei Hu Shou, suddenly fat then thin). The classics state: "Heat injures qi." And again: "Vigorous fire consumes qi." Therefore, when spleen and stomach are deficient and fire prevails, shortness of breath inevitably occurs, failing to protect the skin and hair, and obstructing the flow of upper jiao qi, resulting in insufficiency. Yin blood is deficient, yang qi is depleted; throughout the body, qi and blood in both yin and yang aspects are reduced, unable to regulate temperature, hence chills and fever occur. The *Lingshu Jing* states: "The Upper Jiao opens and develops, distributing the flavors of grains and food, steaming the skin, filling the body, and moistening the hair, like mist and dew irrigating." This represents stomach qi being balanced and ascending.