风乃天之阳邪，伤人卫气，寒乃阴邪，伤人荣血；同气相感耳。《辨脉篇》所谓风伤卫、寒伤荣
者，谓风寒两感，荣卫俱伤，风则伤卫，寒则伤荣，以言其大概。若夫天之风寒，伤人气血，或中于阴，
或中于阳，无有恒常者也。人之皮毛肌腠，气分为阳，血脉为阴，荣行脉中，卫行脉外。风雨寒暑之中
人也，始于皮肤，皮肤缓则腠理开，开则邪从毛发入，入则抵深，深则毛发立，毛发立则淅然，故皮肤
痛；留而不去，则传舍于络脉。是风寒之邪，皆始伤皮毛之气分，留而不去，而后传舍于经荣者也。《灵
枢经》曰∶伤寒形，乃病形；风伤经脉，经脉乃应。《金匮真言》曰∶八风发邪，以为经风。触五脏邪气
发病，是又寒伤气而风伤荣矣。盖阴阳之道，变化不测，故《内经》自有矛盾之文，以意逆志，庶为得
之，若胶执文辞，又不可与论阴阳矣。至于《伤寒论》之中风，更为不同，非春伤之风，亦非四时所中
之风，即严寒鼓动之气，故中风首节曰∶啬啬恶寒，
淅淅恶风。寒乃阴凝之邪，闭于皮毛之间，故用麻黄汤以发散；风乃鼓动之气，开发皮毛，入于肌腠，故
宜桂枝汤以解肌。是又寒在皮毛而伤气，风入腠理而将伤于荣矣。太阳之气，主于皮毛之间，寒伤太阳，
是以六气相传，七日来复，若入于经荣，则为桃仁承气、抵当汤之血证，不复再传阳明矣。寒伤气，故
曰∶伤寒一日，太阳受之，脉若静者为不传，颇欲吐，若躁烦脉数急者，为传也。又曰∶伤寒二三日，
阳明、少阳证不见者，为不传也。此寒在太阳之表，故有六气之相传，风入于肌腠，故不为传经之邪也。
至于春伤之风，四时所中之风，或伤于皮毛，则为嚏泪喘咳；入于肌腠，则为肌肤不仁，伤于筋骨，则为
痛痹拘挛，入于脉中，或为鼠 ，或为厉疡，久风入中，则为肠风飧泄；或中于腑，即不识人；或中于
脏，舌即难言，口吐涎。此在《灵》、《素》、《金匮》诸经中求之，与《伤寒论》之中风不相同也。
Wind is the Yang pathogenic factor of Heaven, damaging the Wei Qi (Defensive Qi); Cold is the Yin pathogenic factor, damaging the Ying Blood (Nutritive Blood); this is due to the resonance of similar energies. What "Wind damages Wei, Cold damages Ying" stated in the *Bian Mai Pian* (Chapter on Differentiating Pulse) refers to the simultaneous invasion of Wind and Cold, causing damage to both Ying and Wei; among them, Wind primarily damages Wei, and Cold primarily damages Ying, which describes the general principle. As for the natural Wind and Cold, when they damage human Qi and Blood, sometimes they attack the Yin aspect, sometimes the Yang aspect, without any constant rule. The skin, hair, and muscle pores (interstices of skin and muscles) of humans: the Qi aspect belongs to Yang, the blood vessels belong to Yin, Ying Qi circulates within the vessels, and Wei Qi circulates outside the vessels. When pathogens such as wind, rain, cold, and heat invade the human body, they start from the skin. If the skin is lax, the pores open; when the pores are open, pathogens enter through the hair follicles. Upon entry, they penetrate deeply; upon deep penetration, the hair stands erect. When the hair stands erect, one feels chilly and shivering, hence skin pain remains; if the pathogen lingers and does not depart, it transmits to the Luo Collaterals. Thus, Wind and Cold pathogens initially damage the Qi aspect of the skin and hair follicles; if they linger and do not depart, they subsequently transmit to the meridians and Ying Blood. The *Ling Shu Jing* states: "Cold injury affects the form, which is the pathological manifestation; Wind injures the meridians, and the meridians respond accordingly." The *Jin Gui Zhen Yan* states: "The pathogenic factors arising from the Eight Winds become Meridian Winds. Touching the pathogenic factors of the Five Zang Organs leads to disease onset; this is again Cold damaging Qi and Wind damaging Ying." Generally, the Way of Yin and Yang involves unpredictable changes; therefore, the *Nei Jing* naturally contains seemingly contradictory texts. One must use intent to infer the author's will to truly grasp the meaning; otherwise, sticking rigidly to textual words makes it impossible to discuss Yin and Yang. As for "Zhong Feng" (Stroke/Wind Strike) in the *Shang Han Lun* (Treatise on Cold Damage), it is even more different. It is not the Wind injured in Spring, nor the Wind contracted during the four seasons, but rather the Qi driven by severe cold. Therefore, the first section of Zhong Feng states: "Sese aversion to cold, Xixi aversion to wind." Cold is a Yin coagulating pathogen that closes between the skin and hair follicles; thus, Mahuang Tang (Ephedra Decoction) is used to disperse it. Wind is a driving Qi that opens the skin and hair follicles, entering the muscle pores; thus, Guizhi Tang (Cinnamon Twig Decoction) is suitable to resolve the muscle layer. This indicates that Cold is at the skin/hair follicle level and damages Qi, while Wind enters the interstices and is about to damage Ying. The Qi of Taiyang (Greater Yang) governs the area between the skin and hair follicles. When Cold damages Taiyang, the Six Qi transmit sequentially, completing a cycle in seven days. If the pathogen enters the meridians and Ying Blood, it becomes a Blood syndrome treated by Taoren Chengqi Tang (Peach Kernel and Rhubarb Decoction) or Didang Tang (Wait-and-See Decoction), and no longer transmits to Yangming. Since Cold damages Qi, it is said: "On the first day of Cold Damage, Taiyang is affected; if the pulse is calm, there is no transmission. If there is a strong desire to vomit, or restlessness with a rapid and urgent pulse, there is transmission." It also says: "On the second and third days of Cold Damage, if Yangming and Shaoyang syndromes are not seen, there is no transmission." This is because Cold is at the exterior of Taiyang, allowing for the sequential transmission of the Six Qi. Wind entering the muscle pores is not a pathogen of meridian transmission. As for the Wind injured in Spring or the Wind contracted during the four seasons, if it injures the skin and hair follicles, it causes sneezing, tearing, wheezing, and coughing; if it enters the muscle pores, it causes insensitivity of the skin and flesh; if it injures the sinews and bones, it causes painful bi-syndrome and spasms; if it enters the vessels, it may cause scrofula (lymph node tuberculosis) or malignant ulcers; if chronic Wind enters internally, it causes intestinal wind and undigested stool diarrhea; if it strikes the Fu Organs, it leads to loss of consciousness; if it strikes the Zang Organs, speech becomes difficult, and saliva drools from the mouth. These can be found in classics such as the *Ling Shu*, *Su Wen*, and *Jin Gui Yao Lue*, and are different from "Zhong Feng" in the *Shang Han Lun*.