疫之传有九。然亦不出表里之间而已。但表而不里者。其证头疼身痛发热。而复
凛凛。内无胸满等证。谷食如常。此邪传外。由肌表而出。或斑消。或汗解为顺。轻剂
可愈。有汗出不彻而热不退者。宜白虎汤。或斑出不透而热不退者。宜举斑汤。有
斑汗并行而并不透者。合用前汤。
但里不表者。惟胸膈痞闷。欲吐不吐。吐而不快。宜瓜蒂散。若邪传里之中下者。心
腹胀满。不吐不呕。或燥结便闭。或热结旁流。或协热下利。或大肠胶闭。并宜承气
辈。有里而再发。或至于三。皆根据前法。
表而再表者。所发未尽。膜原尚有隐伏之邪。故三四日后。根据前发热。脉洪而数。及
其解也。斑者仍斑。汗者仍汗而愈。至于三表者。亦稀有也。
表里分传。始则邪气伏于膜原。尚在半表半里。二证俱现。必先通其里。令里邪去。
自能达表。或斑或汗。随其性而升泄之也。病退而热未除者。膜原尚有未尽之邪
也。宜三消饮调之。若分传至再至三。未之频见。照前同治。
有再表再里。或再表里分传者。医家不解。反责病患不善调养。以致反复。病家不
解。每咎医师疏于救治。彼此归怨。胥失之矣。不知病势之当然。其气性如此。
先表而后里者。始则但有表证。而无里证。宜达原饮。有经证者。当根据三阳加法。继
而脉大且数。自汗而渴。邪离膜原。未能出表。宜白虎汤。辛凉解散。邪从汗解。脉静
身凉而愈。二三日后。或四五日后。依然发热。宜达原饮。至后反加胸满腹胀。不思
谷食。烦渴等证。加大黄微利之。
疫病的传变有九种情况。然而，这些情况也不超出表证和里证的范畴。
仅表现为表证而不涉及里证的情况：其症状为头痛、身体疼痛、发热，并且伴有明显的恶寒（凛凛），内部没有胸膈满闷等症状，饮食如常。这是邪气向外传变，从肌表排出。或者通过出斑消退，或者通过出汗而解，这属于顺证。使用轻剂即可治愈。如果有汗出但不透彻导致热势不退的，适宜用白虎汤。或者有斑疹发出但不透畅导致热势不退的，适宜用举斑汤。如果斑疹和汗出并行但都不透畅的，应当将上述两种方剂合用。
仅表现为里证而不涉及表证的情况：只有胸膈部痞塞闷胀，想吐却吐不出来，吐出来也不畅快，适宜用瓜蒂散。如果邪气传入里的中下部位，出现心腹胀满，不吐不呕，或者是燥屎内结导致便秘，或者是热结旁流（燥屎内结而水液从旁流出），或者是协热下利（伴随发热的腹泻），或者是大肠胶闭（大便干结难下），都适宜用承气汤类的方剂。如果是里证反复发作，甚至达到三次，都依据前面的方法治疗。
表证反复出现的情况：说明之前的病邪未完全清除，膜原（半表半里之隙）仍有潜伏的邪气。所以在三四天后，再次出现之前的发热症状，脉象洪大而数。等到病邪解除时，该出斑的仍然出斑，该出汗的仍然出汗而痊愈。至于进行三次“表法”治疗的，也极为罕见。
表里分传的情况：起初邪气伏匿在膜原，尚处于半表半里的状态，表证和里证同时出现。必须先疏通里气，使里邪去除，自然能达于体表。或者通过出斑，或者通过出汗，顺应病势将其升发宣泄。如果病情减退但热势未除，说明膜原仍有未尽的邪气，适宜用三消饮来调理。如果分传的情况反复一至两次或三次，虽然不常见，但仍按照前面的方法同治。
有先解表后攻里，或者先解表再攻里，或者表里分传又反复的情况。医生不理解这一点，反而责怪病人不善调养，导致病情反复。病人不理解，往往指责医生救治疏忽，彼此互相埋怨，这都是失误。不知道这是病势发展的必然结果，疾病的性质就是如此。
先解表而后攻里的情况：起初只有表证，而没有里证，适宜用达原饮。如果有经证（六经辨证中的特定证候），应当根据三阳经的加减法进行治疗。继而脉象变大且快，自汗出且口渴，说明邪气离开膜原，但未能完全出于体表，适宜用白虎汤，以辛凉之法解散邪气，使邪气随汗而解，脉象平静、身体凉爽而痊愈。过了两三天，或者四五天，依然发热，适宜再用达原饮。到了后期反而出现胸满、腹胀、不思饮食、烦躁口渴等症状，加大黄轻微通下。
The transmission of epidemic diseases encompasses nine patterns. However, these do not extend beyond the categories of Exterior (Biao) and Interior (Li).
**Exterior-only presentation:** The symptoms include headache, body pain, fever, and pronounced aversion to cold (lin lin). There are no internal signs such as chest fullness, and appetite remains normal. This indicates that the pathogenic factor is transmitting outward and exiting via the muscle-surface. Favorable outcomes occur either through the resolution of macules (ban) or through sweating. Mild prescriptions can effect a cure. If sweating is incomplete and fever persists, Baihu Tang (White Tiger Decoction) is indicated. If macules fail to emerge fully and fever persists, Jubang Tang (Macule-Ascending Decoction) is indicated. If both macules and sweat appear but neither is thorough, the aforementioned decoctions should be combined.
**Interior-only presentation:** Symptoms are limited to stuffiness and oppression in the chest and diaphragm, with an urge to vomit but inability to do so, or vomiting without relief. Genti San (Melon Stamen Powder) is indicated. If the pathogen transmits to the middle and lower Interior, presenting with abdominal distension and fullness, absence of vomiting, dry stool constipation, heat-binding with peripheral flow (xie re pang liu), diarrhea accompanied by fever (xie re xia li), or fecal impaction in the large intestine, formulas from the Chengqi Tang (Gut-Purging Decoction) category are appropriate. If Interior syndrome recurs or occurs up to three times, treatment follows the preceding methods.
**Repeated Exterior resolution:** This indicates that the initial pathogenic factors were not fully cleared, and latent pathogens remain in the Membrane Source (Mo Yuan). Consequently, after three or four days, the previous fever returns, with a surging and rapid pulse. Upon resolution, those who should have macules will still manifest them, and those who should sweat will still sweat, leading to recovery. Treatment involving three rounds of Exterior resolution is extremely rare.
**Simultaneous Exterior and Interior transmission:** Initially, the pathogen lies dormant in the Membrane Source, occupying the Half-Exterior Half-Interior position, with both Exterior and Interior syndromes present. One must first unblock the Interior to eliminate Interior pathogens, allowing them to reach the Exterior. They are then expelled upward and outward through macules or sweat, following their natural tendency. If the disease recedes but fever remains, residual pathogens persist in the Membrane Source; Sanxiao Yin (Three-Draining Decoction) is indicated. If this pattern recurs once, twice, or thrice—though uncommon—it is treated according to the prior protocols.
Physicians often misunderstand cases involving repeated Exterior resolution followed by Interior purging, or complex simultaneous transmissions. Instead of understanding the pathology, they blame patients for poor self-care, while patients blame physicians for negligence. This mutual resentment is erroneous. It fails to recognize that this progression is inherent to the disease's momentum and nature.
**Exterior resolution followed by Interior purging:** Initially, only Exterior symptoms are present, with no Interior signs. Danyuan Yin (Origin-Reaching Decoction) is indicated. If meridian syndromes are involved, modifications based on the Three Yang channels should be applied. Subsequently, if the pulse becomes large and rapid, accompanied by spontaneous sweating and thirst, it indicates the pathogen has left the Membrane Source but has not yet fully exited the Exterior. Baihu Tang (White Tiger Decoction) is indicated to release the pathogen via sweating using acrid-cool dispersing methods, resulting in a calm pulse, cool body, and recovery. If fever persists after two to five days, Danyuan Yin (Origin-Reaching Decoction) is used again. If later symptoms such as chest fullness, abdominal distension, loss of appetite, irritability, and intense thirst develop, Rhubarb (Dahuang) is added to induce mild purgation.