尝谓从鱼际至高骨。却行一寸。故谓之寸。从尺泽至高骨。却行一尺。故谓之尺。尺肤者。尺泽至高骨之肤
也。盖气口为肺之脉。皮肤为肺之合。脉行肤内。肤在脉外。故视肤而有取乎尺也。其视之之法有六。曰缓、
曰急、曰滑、曰涩、曰贲而起、曰减而少气。夫缓者尺肤纵缓不急也。急者尺肤紧急不缓也。滑则不涩。而有
流利之容。涩则不滑。而有蹇滞之貌。贲而起者。沸起之状。减而少气者。损少之形。盖缓则为热。急则为寒。
滑属阳而气淖泽。涩属阴而血凝泣。贲而起者。太过为实。减而少气者。不及为虚。六者合观。变在其中矣。
经曰。脉急者。尺之皮肤亦急。脉缓者。尺之皮肤亦缓。脉滑者。尺之皮肤亦滑。脉涩者。尺之皮肤亦涩。脉大
者。尺之皮肤亦贲而起。脉小者。尺之皮肤亦减而少气。然则色脉皮肤。皆当相应也。合而观之。亦可推其
顺逆焉。千金云。风病则滑。痹病则涩。气血盛。则尺之肉丰盛。气血虚。则尺之肉亏竭。此亦诊尺之要也。论
疾诊尺篇曰。尺肤滑。其淖泽者。风也。尺肉弱者。解 。安卧脱肉者。寒热不治。尺肤滑而泽脂者。风也。尺肤
涩者。风痹也。尺肤粗如枯鱼之鳞者。水 饮也。尺涩脉滑。谓之多汗。尺寒脉细。谓之后泄。尺粗常热者。谓
之热中。尺坚大。脉小甚少。气 有加。立死。是又诊尺肤以参脉证。参脉证以决死生矣。至若尺之部位。手
之寒温。因切而知者。容后续述。
我曾说过，从鱼际穴至高骨处，向后量取一寸，所以称为“寸”。从尺泽穴至高骨处，向后量取一尺，所以称为“尺”。尺肤（前臂内侧从尺泽至腕横纹的皮肤），就是尺泽穴至高骨之间的皮肤。因为气口（寸口脉）是肺经的脉搏反映部位，皮肤是肺所合的部位。脉气运行于皮肤之内，皮肤位于脉气之外，所以通过观察皮肤可以获取关于尺部的信息。
观察尺肤的方法有六种：即缓、急、滑、涩、贲而起、减而少气。所谓“缓”，是指尺肤松弛舒缓而不紧急；所谓“急”，是指尺肤紧张紧急而不舒缓。“滑”则不涩，具有流利润泽的形态；“涩”则不滑，具有蹇滞不畅的形态。“贲而起”是指像水沸腾一样隆起的状态；“减而少气”是指虚弱减少的形态。一般来说，缓主热证，急主寒证。滑属阳，表现为气机淖泽（滋润）；涩属阴，表现为血液凝滞不畅。贲而起者，属于太过，为实证；减而少气者，属于不及，为虚证。综合观察这六种情况，病变的变化就包含在其中了。
《内经》说：脉象紧急的，尺部的皮肤也紧急；脉象缓和的，尺部的皮肤也缓和；脉象滑利的，尺部的皮肤也滑利；脉象涩滞的，尺部的皮肤也涩滞；脉象大的，尺部的皮肤也贲然而起；脉象小的，尺部的皮肤也减弱且少气。既然这样，面色、脉象和皮肤表现都应当相互对应。结合起来观察，也可以推断病情的顺逆。
《千金方》说：风病则脉滑，痹病则脉涩。气血旺盛，则尺部的肌肉丰盛；气血虚弱，则尺部的肌肉亏竭。这也是诊察尺部的重要方法。《灵枢·论疾诊尺篇》说：尺肤滑润且光泽的，是风病；尺部肌肉瘦弱的，是懈怠无力（解㑊）；嗜睡卧、肌肉脱失的，是寒热错杂且难治之症；尺肤滑润且有油脂感的，是风病；尺肤涩滞的，是风痹；尺肤粗糙如枯鱼鳞片状的，是水饮内停；尺部皮肤涩而脉象滑的，称为多汗；尺部寒冷而脉象细的，称为后泄（腹泻）；尺部粗大且经常发热的，称为热中（内脏热盛）；尺部坚硬粗大但脉象小且微弱，说明邪气有余，正气不足，会立即死亡。这又是通过诊察尺肤来参考脉证，结合脉证来判断生死预后。至于尺部的具体部位划分、手部的寒温变化，是通过切脉而知晓的，容许后续再详细叙述。
I have stated that from the Yuji (LU10) acupoint to the high bone, measuring backward one cun is therefore called "cun." From the Chize (LU5) acupoint to the high bone, measuring backward one chi is therefore called "chi." The Chi-fu (skin of the forearm) refers to the skin between the Chize acupoint and the high bone. Since the Qi-kou (Cunkou pulse) is the pulse site of the Lung meridian, and the skin is the exterior correspondence of the Lung, with pulse qi circulating within the skin and the skin situated outside the pulse, observing the skin allows for assessment of the Chi region.
The methods for observing the Chi-fu include six types: Huan (Lax), Ji (Tight), Hua (Slippery), Se (Choppy), Ben Er Qi (Bulging and Rising), and Jian Er Shao Qi (Reduced and Deficient in Qi). "Huan" means the Chi-fu is lax and relaxed without tension; "Ji" means the Chi-fu is tight and urgent without relaxation. "Hua" implies not choppy, possessing a smooth and slippery appearance; "Se" implies not slippery, possessing a rough and stagnant appearance. "Ben Er Qi" describes a state resembling boiling water rising; "Jian Er Shao Qi" describes a form of depletion and deficiency. Generally, Huan indicates Heat, while Ji indicates Cold. Hua belongs to Yang, characterized by moist and lubricated Qi; Se belongs to Yin, characterized by coagulated and sluggish Blood. Ben Er Qi indicates excess due to overabundance (Shi); Jian Er Shao Qi indicates deficiency due to insufficiency (Xu). Observing these six aspects together reveals the variations of pathology within.
The Classics state: When the pulse is Ji (Tight), the skin of the Chi region is also Ji; when the pulse is Huan (Lax), the skin of the Chi region is also Huan; when the pulse is Hua (Slippery), the skin of the Chi region is also Hua; when the pulse is Se (Choppy), the skin of the Chi region is also Se; when the pulse is Da (Large), the skin of the Chi region bulges and rises; when the pulse is Xiao (Small), the skin of the Chi region is reduced and deficient in Qi. Thus, facial color, pulse, and skin manifestations should all correspond. By combining them for observation, one can deduce the favorable or unfavorable course of the disease.
The *Qianjin Fang* states: In Wind diseases, the pulse is Hua (Slippery); in Bi syndrome (Painful Obstruction), the pulse is Se (Choppy). When Qi and Blood are abundant, the flesh of the Chi region is plump; when Qi and Blood are deficient, the flesh of the Chi region is emaciated. This is also a key method for diagnosing the Chi region. The chapter "Lun Ji Chi Pian" in the *Lingshu* states: If the Chi-fu is slippery and glossy, it is Wind disease; if the Chi-region flesh is weak, it is Xie Jie (lethargy and weakness); if there is a tendency to lie down, muscle wasting, it is a difficult-to-treat condition of alternating cold and heat; if the Chi-fu is slippery and oily, it is Wind disease; if the Chi-fu is rough, it is Feng Bi (Wind-Bi); if the Chi-fu is coarse like the scales of a dried fish, it is Water Retention (Shui Yin); if the Chi-fu is Se (rough) but the pulse is Hua (slippery), it is termed excessive sweating; if the Chi region is cold and the pulse is Xi (Fine), it is termed Hou Xie (posterior discharge/diarrhea); if the Chi region is thick and constantly hot, it is Re Zhong (internal heat); if the Chi region is hard and large but the pulse is small and scarce, indicating excess pathogenic factors and insufficient healthy Qi, death will occur immediately. This further illustrates using Chi-fu diagnosis to reference pulse and symptoms, and combining pulse and symptoms to determine life and death prognosis. As for the specific locations of the Chi region and the coldness or warmth of the hands, which are known through palpation, I reserve detailed discussion for later.