帝曰∶决其生死奈何？岐伯曰∶反其目视之，其中有赤脉，上下贯瞳子，见一脉，一岁死；见一脉半，一
岁半死；见二脉，二岁死；见二脉半，二岁半死；见三脉，三岁死。赤脉不下贯瞳子，可治也。
黑珠属肝，瞳子属肾，赤脉贯瞳子，邪毒深入肝肾之脏，必死矣。赤脉多，其血气盛，故死期延迟。若虽
有赤脉，而不下贯瞳子者，毒犹在经而未入脏，可以治之也。
《素问·热论篇》帝曰∶今夫热病者，皆伤寒之类也。或愈或死，其死皆以六七日间，其愈皆十日以上
者，何也？岐伯曰∶巨阳者，诸阳之属也，其脉连于风府，故为诸阳之气也。人之伤于寒也，则为病热，热虽
甚不死；其两感于寒而病者，必不免于死。
此统标热病，而言皆伤寒之类者，谓多由伤寒邪而化热，不独感热而成也。巨阳者，太阳经也，风府，项
后督脉穴，督脉为阳脉之纲，太阳经主一身之表，又与督脉相通，故为诸阳主气也。
伤于寒而病热者，以身中阳旺，被邪遏而化热，以其阳旺，故热虽甚不死；其两感于寒者，谓外太阳、内少阴，
俱受邪伤，而本元气绝，故不免于死也。
伤寒一日，巨阳受之，故头项痛，腰脊强；二日，阳明受之，阳明主肉，其脉挟鼻络于目，故身热目疼而
鼻干，不得卧也；三日，少阳受之，少阳主胆，其脉循胁络于耳，故胸胁痛而耳聋。三阳经络皆受病，而未入
于脏者，故可汗而已。四日，太阴受之，太阴脉布胃中，络于嗌，故腹满而嗌干；五日，少阴受之，少阴脉
贯肾络于肺，系舌本，故口燥舌干而渴；六日，厥阴受之，厥阴脉循阴器而络于肝，故烦满而囊缩。三阴三
阳、五脏六腑皆受病，营卫不行，五脏不通，则死矣。其不两感于寒者，七日，巨阳病衰，头痛少愈；八日，
阳明病衰，身热少愈；九日，少阳病衰，耳聋微闻；十日，太阴病衰，腹减如故，则思饮食；十一日，少阴病
衰，渴止不满，舌干已而嚏∶十二日，厥阴病衰，囊纵，少腹微下，大气皆去，病日已矣。帝曰∶治之奈
何？岐伯曰∶治之各通其脏脉，病日衰已。其未满三日者，可汗而已；其满三日者，可泄而已。
此明表邪自浅入深之次序也。盖人身阳气，卫外而为固者，卫气昼行于阳，夜行于阴，行于阴则表阳虚，
邪得乘虚而内侵。卫气一日出入一次，故邪一日内侵一经，而六经是浅深之层次，故至第六日，深入第六层厥
阴之经也。太阳为第一层，其经脉自足行腰背上头，故头项痛，腰脊强，余皆观其病状，知其邪在何
经。若六经腑脏皆受邪，营卫闭塞不行，五脏之气不通，则死，故死皆以六七日间，此言其邪重者也。若非阴
阳两感之邪，但由阳经递传阴经，而未伤脏腑，则七日元气来复，而邪亦逐日渐衰，故至十二日后，病可愈也。
若治之，必疏其经络，以通达脏气之脉，则邪可衰去。如未满三日，邪在阳经，可发表而汗之；已满三日，邪
之阴经，当从阴分泄之。泄之者，或腑气不通，则通其腑，而阴经之邪，可随之而泄矣。盖阴经在里，不能
发汗也。《灵枢·邪客病形篇》曰∶邪中阴经而入脏，脏气实，邪不能客，则还之于腑。可知邪由阴经而归胃
腑者，其脏气必实。如仲景所论少阴证用承气汤者是也。其脏气虚者，邪由阴经入脏，必死矣。若由阳经而入
腑者，亦为实证也。然经文止明其常理如此，而邪之传变无定，固不可拘执日数而治。所以仲景着论，要必先
辨脉证，知其邪在何经何腑，或虚或实，随宜施治，立法最为精详，是故学人首当究心，奉为圭臬也。
黄帝问：如何判断病人的生死预后？岐伯回答：观察病人眼睛的反光，如果眼球中有赤色的血脉，上下贯穿瞳孔，见到一条赤脉，预示一年死；见到一条半赤脉，预示一年半死；见到两条赤脉，预示两年死；见到两条半赤脉，预示两年半死；见到三条赤脉，预示三年死。如果赤色血脉不向下贯穿瞳孔，是可以治疗的。黑珠（黑眼仁）属于肝，瞳孔属于肾，赤色血脉贯穿瞳孔，说明邪毒深入肝肾之脏，必然死亡。赤脉多，说明血气旺盛，所以死亡时间会推迟。如果有赤色血脉，但不向下贯穿瞳孔，说明毒邪还在经络而未进入脏腑，可以治疗。
《素问·热论篇》记载：黄帝问：现在的热病，都属于伤寒这一类。有的痊愈，有的死亡，死亡的多发生在发病后六七天之间，痊愈的多在十天以上，这是为什么呢？岐伯回答：巨阳经（即太阳经），是诸阳经的统领，它的经脉连接风府穴，所以它是统摄诸阳气的经脉。人受寒邪侵袭，就会患热病，热势虽然严重但不会致死；如果是阴阳两经同时感受寒邪而发病的，就一定难免于死亡。
这里总括标热病，说它们都属于伤寒一类，意思是大多由伤寒邪气转化而来，不仅仅是感受热邪所致。巨阳经就是太阳经，风府是项后督脉上的穴位，督脉是阳脉的纲领，太阳经主管一身之表，又与督脉相通，所以它是诸阳经主气的经脉。
受寒邪侵袭而患热病的，是因为体内阳气旺盛，被邪气遏制而化热，因为阳气旺盛，所以热势虽重也不会致死；所谓“两感于寒”，是指外层的太阳经和内层的少阴经同时受到邪气伤害，导致本元元气断绝，所以难免死亡。
伤寒第一天，巨阳经受邪，所以出现头项疼痛、腰脊僵硬；第二天，阳明经受邪，阳明经主肌肉，其经脉挟鼻络目，所以出现身体发热、眼睛疼痛、鼻子干燥、无法安卧；第三天，少阳经受邪，少阳经主胆，其经脉循行胁肋络耳，所以出现胸胁疼痛和耳聋。三阳经的经络都受病，但尚未传入脏腑，所以可以通过发汗的方法治愈。第四天，太阴经受邪，太阴经的经脉散布胃中，联络咽喉，所以出现腹部胀满和咽喉干燥；第五天，少阴经受邪，少阴经的经脉贯穿肾脏联络肺脏，系连舌根，所以出现口燥舌干而口渴；第六天，厥阴经受邪，厥阴经的经脉循行生殖器并联络肝脏，所以出现心烦腹满和阴囊收缩。如果三阴三阳、五脏六腑都受病，营卫之气运行停滞，五脏气机不通，就会死亡。那些没有发生阴阳两感的病人，第七天，巨阳经的病势衰退，头痛稍微减轻；第八天，阳明经的病势衰退，身体发热稍微减轻；第九天，少阳经的病势衰退，耳聋能微微听到声音；第十天，太阴经的病势衰退，腹部胀满消退恢复常态，开始想吃饭；第十一天，少阴经的病势衰退，口渴停止，腹胀消除，舌干好转并开始打喷嚏；第十二天，厥阴经的病势衰退，阴囊松弛，小腹轻微下坠，大部的邪气都已去除，病一天天好了。黄帝问：怎么治疗呢？岐伯回答：治疗要分别疏通各脏腑的经脉，病势就会一天天衰退痊愈。病程未满三天的，可以通过发汗治愈；病程已满三天的，可以通过泄下法治愈。
这里阐明表邪由浅入深的次序。大概人身体的阳气，具有护卫体表而固密的作用，卫气白天行于阳分，夜晚行于阴分，行于阴分时体表阳气虚弱，邪气得以乘虚内侵。卫气一天出入一次，所以邪气一天内侵一经，六经就是深浅的层次，所以到第六天，邪气深入第六层厥阴经。太阳经是第一层，其经脉从足部经过腰背上行至头部，所以出现头项痛、腰脊强，其余的情况都是观察病症表现，就知道邪气在哪条经。如果六经脏腑都受邪，营卫闭塞不行，五脏之气不通，就会死亡，所以死亡多发生在六七天之间，这是指邪气重的情况。如果不是阴阳两感的邪气，只是由阳经依次传入阴经，且未伤及脏腑，那么第七天元气来复，邪气也逐日衰退，所以到十二天后，病可以痊愈。如果进行治疗，必须疏通经络，以通达脏腑之气，那么邪气就可以衰退去除。如病程未满三天，邪气在阳经，可以发表发汗；已满三天，邪气在阴经，应当从阴分泄下。所谓泄下，或者是腑气不通，就通利腑气，那么阴经的邪气，就可以随之而泄出。因为阴经在里，不能发汗。《灵枢·邪客病形篇》说：邪气侵入阴经进入脏腑，如果脏气充实，邪气不能停留，就会返还到腑。可知邪气由阴经归并于胃腑的，其脏气必定充实。如张仲景所论述的少阴证使用承气汤的情况就是这样。如果脏气虚弱，邪气由阴经进入脏腑，必然死亡。如果由阳经进入腑，也属于实证。然而经文只明确说明了常理如此，而邪气的传变没有定数，本来就不能拘泥于日数来治疗。所以张仲景著论，一定要先辨别脉象和症状，知道邪气在哪经哪腑，或者虚或者实，根据适宜情况施治，立法最为精详，因此学习者首先应当用心研究，奉为准则。
Huangdi asked: How can one determine life and death? Qibo replied: Observe the reflection in the patient's eyes. If there are red vessels penetrating vertically through the pupil, seeing one red vessel indicates death within one year; seeing one and a half red vessels indicates death within one and a half years; seeing two red vessels indicates death within two years; seeing two and a half red vessels indicates death within two and a half years; seeing three red vessels indicates death within three years. If the red vessels do not penetrate downward through the pupil, it is treatable. The black part of the eye (cornea/iris area) belongs to the Liver, and the pupil belongs to the Kidney. Red vessels penetrating the pupil indicate that pathogenic toxins have deeply invaded the Zang organs of the Liver and Kidney, which is invariably fatal. An abundance of red vessels suggests abundant Qi and Blood, thus delaying the time of death. If there are red vessels but they do not penetrate downward through the pupil, the toxin remains in the meridians and has not entered the Zang organs, so it can be treated.
In the *Suwen: Re Lun* chapter: Huangdi asked: Current febrile diseases all belong to the category of Cold Damage (Shanghan). Some recover, some die; those who die usually do so between the sixth and seventh days, while those who recover usually take more than ten days. Why is this? Qibo replied: Ju Yang (Giant Yang), which refers to the Taiyang Meridian, is the leader of all Yang meridians. Its vessels connect to the Fengfu acupoint, thus governing the Qi of all Yang meridians. When humans are injured by Cold pathogens, they develop febrile diseases. Even if the heat is severe, it will not cause death; however, for those suffering from "Liang Gan" (simultaneous infection of Yin and Yang meridians) due to Cold, death is inevitable.
This section summarizes marked febrile diseases, stating they all belong to the category of Cold Damage, meaning they mostly arise from the transformation of Cold Damage pathogens into heat, rather than solely from direct heat invasion. Ju Yang refers to the Taiyang Meridian. Fengfu is an acupoint on the Du Meridian at the back of the neck. The Du Meridian is the commander of all Yang meridians. The Taiyang Meridian governs the exterior of the body and connects with the Du Meridian, thus serving as the master of Qi for all Yang meridians.
Those injured by Cold and developing heat do so because their internal Yang Qi is robust, which is constrained by the pathogen and transforms into heat. Because Yang Qi is robust, even severe heat will not cause death. "Liang Gan on Cold" refers to the simultaneous injury of the exterior Taiyang and interior Shaoyin meridians by pathogens, leading to the exhaustion of primordial Yuan Qi, hence death is inevitable.
On the first day of Cold Damage, the Ju Yang meridian receives the pathogen, resulting in headache, stiff neck, and stiffness/pain in the lower back and spine. On the second day, the Yangming meridian receives the pathogen. Yangming governs flesh, and its vessels run alongside the nose and connect to the eyes, resulting in fever, eye pain, dry nose, and inability to lie down. On the third day, the Shaoyang meridian receives the pathogen. Shaoyang governs the Gallbladder, and its vessels follow the costal region and connect to the ears, resulting in hypochondriac pain and deafness. If the meridians of the Three Yang are diseased but have not yet entered the Zang organs, they can be cured by inducing sweating. On the fourth day, the Taiyin meridian receives the pathogen. Taiyin vessels distribute in the stomach and connect to the throat, resulting in abdominal fullness and dry throat. On the fifth day, the Shaoyin meridian receives the pathogen. Shaoyin vessels pass through the Kidneys, connect to the Lungs, and attach to the root of the tongue, resulting in dry mouth, dry tongue, and thirst. On the sixth day, the Jueyin meridian receives the pathogen. Jueyin vessels follow the genitalia and connect to the Liver, resulting in irritability, abdominal fullness, and retraction of the scrotum. If the Three Yin and Three Yang, as well as the Five Zang and Six Fu organs, are all diseased, and Ying and Wei Qi cease to circulate, and the Qi of the Five Zang becomes blocked, death ensues. For those not suffering from Liang Gan, on the seventh day, the disease in the Ju Yang meridian declines, and headache slightly improves. On the eighth day, the disease in the Yangming meridian declines, and fever slightly subsides. On the ninth day, the disease in the Shaoyang meridian declines, and hearing slightly returns. On the tenth day, the disease in the Taiyin meridian declines, abdominal distension decreases to normal, and appetite returns. On the eleventh day, the disease in the Shaoyin meridian declines, thirst stops, abdominal fullness resolves, tongue dryness improves, and sneezing occurs. On the twelfth day, the disease in the Juevin meridian declines, the scrotum relaxes, slight lower abdominal depression occurs, major pathogenic factors are expelled, and the disease heals day by day. Huangdi asked: How should it be treated? Qibo replied: Treatment requires unblocking the meridians of each respective Zang organ, so the disease will decline and heal day by day. If the duration is less than three days, it can be cured by sweating; if the duration is three days or more, it can be cured by purging/draining.
This clarifies the sequence of external pathogens moving from shallow to deep. Generally, the body's Yang Qi protects the exterior and maintains solidity. Wei Qi travels in the Yang aspects during the day and in the Yin aspects at night. When traveling in the Yin, the exterior Yang becomes deficient, allowing pathogens to invade internally due to deficiency. Wei Qi completes one cycle of entry and exit daily; thus, pathogens invade one meridian per day. The Six Meridians represent layers of depth. By the sixth day, the pathogen reaches the deepest layer, the Jueyin meridian. Taiyang is the first layer; its vessels travel from the foot, up the waist and back, to the head, causing headache, stiff neck, and back stiffness. In other cases, observing symptoms reveals which meridian is affected. If all Six Meridians and Zang-Fu organs are invaded, and Ying-Wei circulation is blocked with Zang Qi uncommunicated, death results. Hence, death often occurs around the sixth or seventh day, indicating heavy pathogenic influence. If not Liang Gan, but merely sequential transmission from Yang to Yin meridians without damaging Zang organs, Yuan Qi recovers on the seventh day, and pathogens decline daily, allowing recovery after twelve days. Treatment must unblock meridians to facilitate the flow of Zang Qi, thereby reducing pathogens. If less than three days, with pathogens in Yang meridians, release the exterior via sweating; if three days or more, with pathogens in Yin meridians, drain them from the Yin aspect. Draining may involve unblocking Fu Qi if there is obstruction, allowing Yin meridian pathogens to be expelled. Since Yin meridians are interior, sweating is inappropriate. The *Lingshu: Xie Ke Bing Xing* chapter states: When pathogens enter Yin meridians and reach Zang organs, if Zang Qi is solid, pathogens cannot reside and return to the Fu organs. This implies that when pathogens move from Yin meridians to the Stomach Fu, Zang Qi must be solid. This aligns with Zhang Zhongjing’s discussion of using Chengqi Tang for Shaoyin patterns. If Zang Qi is deficient, pathogens entering Zang organs from Yin meridians lead to death. Pathogens entering Fu organs from Yang meridians also constitute excess patterns. However, the classic text only outlines general principles; pathogenic transmission is variable and cannot be rigidly bound by day counts. Therefore, Zhang Zhongjing emphasized differentiating pulse and symptoms first to identify the meridian and Fu/Zang involvement, and whether the pattern is deficiency or excess, applying treatment accordingly. His legislation is most precise and detailed, making it essential for students to study and adopt as a standard.