热入血室三条，其旨不同。第一条，是血舍空而热乃入者，空则热不得聚，而游其部，
故胸
胁满。第二条，是热邪与血俱结于血室者，血结亦能作寒热，柴胡亦能去血结，不独和解之
谓矣。第三条，是热邪入而结，经尚行者，经行则热亦行而不得留，故必自愈，无犯胃气及
上二焦，病在血而不在气，在下而不在上也。若诛伐无过，变证随出，乌能自愈耶？
下利，寸脉反浮数者，阳之盛也；尺中自涩者，阴之虚也。以阳加阴，必圊脓血。
少阴热在膀胱而便血者，脏邪还腑，血去热出，当愈；强发少阴汗而动血者，热邪内迫
，血去阴竭，多死。
少阴病吐利，烦躁，四逆者死，为阴极而阳绝也；少阴吐利，手足厥冷，烦躁欲死者，
吴茱萸汤主之，为阴盛而阳争也。病症则同，而辨之于争与绝之间，盖亦微矣。
亡阳，阳不守也；无阳，阳之弱也。阳亡者，藩篱已彻，故汗出不止；阳弱者，施化无
权，故不能作汗。
阳为津液之源，津液为阳之根。汗出过多，胃气生热，津液竭矣。阳气虽存，根本则离
，故曰绝阳。
伤寒脉促，手足厥逆者，可灸之。按本论云∶脉阳盛则促，则手足厥逆。而脉促者，非
阳之虚，乃阳不通也；灸之，所以引阳外通。若厥而脉微者，则必更以四逆温之。
病患手足厥冷，脉乍紧者，邪结在胸中。胸中，阳也，阳实气于四肢。邪结胸中，其阳
不布
，则手足无气而厥冷。胸邪最高，高者因而越之，故曰当吐之，宜瓜蒂散。脉促者，阳结不
通，故宜引其阳；脉紧者阳为邪遏，故须吐其邪。二者皆与阳虚厥逆不同。
脉微而厥者，阳之虚也，宜四逆辈；脉细而厥者，血虚不营于四末也，宜酸甘辛药温之
、润之、行之，当归四逆是也。
关于“热入血室”的三条论述，其主旨各不相同。第一条，是血室空虚而热邪乘虚进入，因为血室空，热邪无法聚集，便游走于胁肋部位，所以出现胸胁胀满的症状。第二条，是热邪与血液共同结聚在血室，血液结滞也能引起寒热往来，小柴胡汤（Chaihu Tang）不仅能和解少阳，也能消除血结，不仅仅局限于和解的作用。第三条，是热邪进入并结聚，但月经尚在进行中，月经通行则热邪也随之排出而不能停留，所以病证必定自愈，此时不应损伤胃气及上、中二焦的气机，因为病位在血分而不在气分，在下焦而不在上焦。如果错误地攻伐无邪之处，变证就会随之产生，怎么能自愈呢？
下利（腹泻），寸脉反而浮数，这是阳气亢盛的表现；尺脉自涩，这是阴液亏虚的表现。以亢盛的阳气加临于亏虚的阴液，必然导致排泄脓血。
少阴病热邪在膀胱而便血的，属于脏邪传还于腑，血液排出则热邪随之而出，应当痊愈；强行发汗治疗少阴病而动血者，热邪内迫，血液流失导致阴液枯竭，大多死亡。
少阴病出现呕吐、下利、烦躁、四肢厥冷的，属于死证，这是因为阴气极盛而阳气断绝；少阴病出现呕吐、下利、手足厥冷、烦躁欲死的，应用吴茱萸汤（Wuzhuyu Tang）主治，这是因为阴寒盛而阳气与之抗争所致。病症虽然相同，但在“抗争”与“断绝”之间进行辨别，其中的差异极其细微。
亡阳，是指阳气不能固守；无阳，是指阳气虚弱。阳气外亡者，卫外之藩篱已破，所以汗出不止；阳气虚弱者，气化功能失去权柄，所以不能出汗。
阳气是津液的源头，津液是阳气的根本。出汗过多，胃气生热，津液枯竭。阳气虽然尚存，但根本已离，所以称为绝阳。
伤寒病脉象急促，手足厥冷的，可以用灸法治疗。按《伤寒论》原文说：脉阳盛则促，对应手足厥逆。而脉促，并非阳气虚弱，而是阳气不通畅；灸法的作用是引导阳气向外通达。如果是厥冷且脉微细的，则必须用四逆汤（Sini Tang）等温阳药物来治疗。
病患手足厥冷，脉搏突然紧实的，是邪气结聚在胸中。胸中属阳，阳气充实才能布达于四肢。邪气结聚在胸中，阳气不能布散，则手足得不到阳气而厥冷。胸中的邪气位置最高，根据“高者因而越之”的原则，所以应当用吐法，适宜使用瓜蒂散（Guiti San）。脉促，是阳气结滞不通，所以适宜引导阳气；脉紧，是阳气被邪气遏制，所以须用吐法祛除邪气。这两种情况都与阳气虚衰导致的厥逆不同。
脉微细而厥冷的，是阳气虚弱，适宜用四逆汤类方剂；脉细弱而厥冷的，是血虚不能濡养四肢末端，适宜用酸甘辛味的药物温煦、滋润、通行，当归四逆汤（Danggui Sini Tang）就是此类方剂。
Regarding the three discussions on "Heat Entering the Blood Chamber" (Re Ru Xue Shi), their main purports differ. The first case refers to heat entering an empty blood chamber; because it is empty, the heat cannot gather and instead wanders in the hypochondriac region, resulting in fullness of the chest and hypochondrium. The second case involves heat pathogen and blood co-aggregating in the blood chamber; blood stasis can also cause alternating chills and fever, and Chaihu Tang (Bupleurum Decoction) can resolve blood stasis, not merely serving a harmonizing function. The third case describes heat entering and aggregating while menstruation is still flowing; as menstruation proceeds, the heat moves with it and cannot remain, so the condition will heal spontaneously. In this scenario, one should not injure the Stomach Qi or the Upper and Middle Jiao, because the disease is in the Blood level rather than the Qi level, and in the Lower Jiao rather than the Upper Jiao. If one wrongly attacks what is not at fault, complications will arise, making spontaneous healing impossible.
In cases of diarrhea (Li), if the Cun pulse is surprisingly floating and rapid, it indicates excess Yang; if the Chi pulse is naturally choppy, it indicates deficiency of Yin. When excess Yang acts upon deficient Yin, purging of pus and blood is inevitable.
In Shaoyin disease, if heat is in the Bladder causing hematochezia, it signifies the transmission of Zang pathogen to Fu organ; once blood is expelled, heat exits, and recovery is expected. However, if one forcibly induces sweating in Shaoyin disease, disturbing the blood, the heat pathogen forces inward, leading to blood loss and exhaustion of Yin, which often results in death.
In Shaoyin disease, vomiting, diarrhea, irritability, and cold extremities indicate a fatal prognosis, representing extreme Yin and absolute Yang failure. Conversely, in Shaoyin disease with vomiting, diarrhea, cold hands and feet, and severe irritability, Wuzhuyu Tang (Evodia Decoction) is indicated, representing Yin excess with struggling Yang. Although the symptoms are similar, the distinction between "struggling" and "failure" is extremely subtle.
"Wang Yang" (Loss of Yang) refers to Yang failing to maintain its position; "Wu Yang" (Absence of Yang) refers to weak Yang. In Yang loss, the defensive barrier is breached, causing unceasing sweating. In Yang weakness, the transformative power is compromised, preventing sweat production.
Yang is the source of Body Fluids, and Body Fluids are the root of Yang. Excessive sweating generates heat in the Stomach and exhausts Body Fluids. Although Yang may still exist, the root has separated, hence termed "Jue Yang" (Absolute Yang).
In Shanghan (Cold Damage) with a Cu (rapid and intermittent) pulse and cold extremities, moxibustion may be applied. According to the original text: a Yang-excess pulse leads to Cu, corresponding to cold extremities. A Cu pulse does not indicate Yang deficiency but Yang obstruction; moxibustion serves to guide Yang outward to unblock it. If there are cold extremities with a faint pulse, Sini Tang (Frigid Extremities Decoction) and similar warming formulas must be used.
When patients have cold extremities and a suddenly tight pulse, it indicates pathogen aggregation in the Chest. The Chest belongs to Yang, and sufficient Yang Qi is required to reach the four limbs. Pathogen aggregation in the Chest prevents Yang distribution, causing cold extremities due to lack of Qi. Since pathogen in the Chest is located high, following the principle "those that are high should be evacuated upwards," emesis is indicated, using Guiti San (Melon Seed Powder). A Cu pulse indicates Yang obstruction, requiring guidance of Yang; a tight pulse indicates Yang suppression by pathogen, requiring expulsion of pathogen via emesis. Both conditions differ from cold extremities caused by Yang deficiency.
A faint pulse with cold extremities indicates Yang deficiency, treated with Sini Tang category formulas. A thin pulse with cold extremities indicates Blood deficiency failing to nourish the four extremities, treated with sour, sweet, and acrid herbs to warm, moisten, and circulate, such as Danggui Sini Tang (Angelica Decoctio Frigidi Extremorum).