内伤及劳役饮食不节病，手心热，手背不热；外伤风寒，则手背热，手心不热。此辨至甚皎然。
若饮食劳役所伤，其外证必显在口，必口失谷
味，必腹中不和，必不欲言，纵勉强对答，声必怯弱，口沃沫多唾，鼻中清涕或有或无，即阴证也。外伤
风寒，则其外证必显在鼻，鼻气不利，声重浊不清利，其言壅塞，盛有力，而口中必和。伤寒则面赤，
鼻壅塞而干，伤风则鼻流清涕而已。《内经》云∶鼻者肺之候，肺气通于天。外伤风寒，则鼻为之不利。口
者坤土地，脾气通于口。饮食失节，劳役所伤，口不知谷味，亦不知五味。又云∶伤食恶食，伤食明矣。
外伤风寒者，故其气壅盛而有余，内伤饮食劳役者，其口鼻中皆气短促，不足以息。何以分之？盖外伤
风寒者，心肺元气初无减损，又添邪气助之，使鼻气壅塞不利，其面赤，其鼻中气不能出，并从口出，
但发一言，必前轻而后重，其言高，其声壮厉而有力。是伤寒则鼻干无涕，面壅色赤，其言前轻后重，
其声壮厉而有力者，乃有余之验也；伤风则决然鼻流清涕，其声嘎，其言响如从瓮中出，亦前轻而后重，
高揭而有力，皆气盛有余之验也。
内伤饮食劳役者，心肺之气先损，为热所伤，热既伤气，四肢无力以动，故口鼻中皆短气少气，上喘懒
语，人有所问，十不欲对其一，纵勉强答之，其气亦怯，其声亦低，是其气短少不足之验也。明白如此，
虽妇人女子亦能辨之，岂有医者反不能辨之乎？
内伤以及因劳累过度、饮食不节制导致的疾病，表现为手心发热，而手背不热；若是外感风寒邪气，则表现为手背发热，而手心不热。这种辨别方法非常清晰明了。
如果是饮食和劳累所致的内伤，其外在证候必然显现在口部：必定口中失去谷物的味道，必定腹部不适，必定不想说话；即使勉强回答，声音也一定怯弱无力，口中流涎多唾，鼻中清涕或有或无，这属于阴证。如果是外感风寒，其外在证候必然显现在鼻部：鼻气不利，声音重浊不清利，言语壅塞不畅，声音盛大有力，而口中味觉正常。患伤寒则面色发红，鼻塞且干燥；患伤风则仅流清涕而已。《内经》说：“鼻是肺的外候，肺气与天相通。”外感风寒，则鼻子因此感到不利。口属坤土（脾），脾气通于口。饮食失节，劳累所伤，口中不知谷物味道，也不知五味之味。又说：“伤食者厌恶食物”，这是很明显的。
外感风寒的人，所以气息壅盛而有余；内伤饮食劳役的人，其口鼻中的气息都短促，呼吸不足。如何区分呢？大概外感风寒的人，心肺的元气起初并没有减损，又增添了邪气助长它，使得鼻气壅塞不利，面色发红，鼻中的气不能从鼻出，都从口出，只要说一句话，一定是前轻后重，声音高亢，声调壮厉而有力。如果是伤寒，表现为鼻干无涕，面色红赤，言语前轻后重，声音壮厉而有力，这是有余（实证）的验证；如果是伤风，则必然流清涕，声音嘶哑，说话响声如同从瓮中发出，也是前轻后重，音调高昂而有力，这些都是气盛有余的验证。
内伤饮食劳役的人，心肺之气先受损，被热邪所伤，热既已伤气，四肢无力活动，所以口鼻中气息都短少，上气喘促，懒于言语，别人有所问，十个里面不愿意回答一个，即使勉强回答，气息也怯弱，声音也低微，这是气短少不足的验证。像这样明白清楚，即使是妇女女子也能辨别，难道有医生反而不能辨别吗？
Diseases caused by internal injury, as well as those due to overexertion and irregular diet, present with heat in the palms (Shouxin) while the backs of the hands (Shoubai) remain cool; conversely, external contraction of Wind-Cold (Fenghan) presents with heat on the backs of the hands while the palms remain cool. This distinction is extremely clear.
If injured by diet and overexertion, the external manifestations must appear at the mouth: there will inevitably be a loss of taste for grain foods, abdominal discomfort, and an unwillingness to speak. Even if answering reluctantly, the voice will necessarily be timid and weak, with excessive saliva and drool. There may or may not be clear nasal discharge; this constitutes a Yin syndrome (Yin zheng). If externally contracted by Wind-Cold, the external manifestations must appear at the nose: nasal breathing will be obstructed, the voice heavy and turbid, speech congested and unsmooth, yet loud and powerful, while the sense of taste in the mouth remains normal. In Cold Damage (Shanghan), the face becomes red, and the nose is congested and dry; in Wind Injury (Shangfeng), only clear nasal discharge occurs. The *Neijing* states: "The nose is the manifestation of the Lung; Lung Qi connects with Heaven." External contraction of Wind-Cold causes nasal obstruction. The mouth belongs to Kun Earth (Spleen); Spleen Qi connects to the mouth. Due to irregular diet and overexertion, one loses the taste for grains and the five flavors. It is also stated: "Those injured by food have an aversion to eating," which is quite evident.
In cases of external Wind-Cold contraction, the Qi is congested, abundant, and excessive. In cases of internal injury from diet and overexertion, the Qi in both the mouth and nose is short and rapid, insufficient for respiration. How are they distinguished? Generally, in external Wind-Cold contraction, the primordial Qi of the Heart and Lungs is initially undiminished, and the pathogenic Qi adds to it, causing nasal congestion and obstruction. The face becomes red, and air cannot exit through the nose but exits through the mouth. When speaking any sentence, the tone is light at the beginning and heavy at the end; the pitch is high, and the voice is vigorous, harsh, and powerful. In Cold Damage, symptoms include a dry nose without discharge, a congested red face, speech that is light at the beginning and heavy at the end, and a vigorous, harsh, and powerful voice; these are signs of excess (Yu). In Wind Injury, there is invariably clear nasal discharge, a hoarse voice, and speech that sounds resonant as if coming from a jar; it is also light at the beginning and heavy at the end, with a high pitch and power; these are all signs of abundant and excessive Qi.
In cases of internal injury from diet and overexertion, the Qi of the Heart and Lungs is first damaged and injured by Heat. Since Heat damages Qi, the limbs become weak and unable to move. Consequently, there is shortness of breath and scanty Qi in both the mouth and nose, upper asthma (wheezing), and reluctance to speak. When asked questions, one is unwilling to answer even one out of ten. Even if answering reluctantly, the Qi is timid and the voice low; these are signs of deficient and insufficient Qi. Such clarity allows even women to distinguish between them; how could a physician fail to do so?