外感身热有汗，为伤风；无汗，为伤寒。盗汗，为邪初传阳明，又为阳入扰阴。
自汗，为阳明邪实，（手足心、腋下皆汗。）又为表虚不固。自汗，分重鼾睡，为风温。服
药后得汗，表应解，不解是汗未彻也。（必汗出至足乃为彻。）头有汗，身无汗，若小便不
利，热渴，则发黄。小便利而大便黑，则为瘀血。若胸满咳喘，则为水气。大抵阳
明实热，不得发越者多。头汗多可下之证。关格证，小便不通，头汗出者死。额上
及手足冷汗者，阴毒也。汗多则津脱而亡阳。凡热汗必涩，（肌肉热而涩也。）冷汗必滑。
（肌肉冷而滑也。）汗味淡而不咸，缀而不流者，为绝汗，即死。心为汗，肝为泪，肺为涕，
脾为涎，肾为唾。妇人病须问经候，若经水适来，或适断，而病热者，热入之，名
曰热入血室。其证胸胁下满，昼日明了，夜则谵语，如见鬼状。呕吐血，皆由胃出。
若倾盆成块而来，或紫黑，（为瘀血。）或鲜红，（为新血。）此太冲、肾、（二经合行。）肝经
之血，由胃并出者也。（雷火势暴，故大出。）若止数口，或一二钟，或红或紫或黑，
此胃经血自出者也。（胃虽多血，然其热不若雷火之暴，故所出比之略少。）咳血者，因咳嗽
而出，痰
中见血丝血点，此乃热伤肺络。肺少血，虽少亦出，恐致肺枯难治。又肺病久及肾，
肾与冲脉并经出入，血从肾冲咳出者，其血必多，（肾虽血少，合冲则多，须知。）其来喉必痒，
或有声响，或有硬气自下冲上。咯唾血者，或随气逆火炎而唾，（不用力。）或随痰而咯，
（用力，痰中有血散漫者是。）此肺肾之血也。上焦血浮，中焦血不沉不浮，下焦血沉，
以水试之可见。衄血，详血门。太阳经血，有从鼻 出者，其经从背上脑注鼻，
不衄则 出也。肠风血鲜，脏毒血黯。溲血，痛为血淋，不痛为尿血，皆与尿同出。
若不与尿同出者，乃从精窍出也。漱水不咽，小便利，大便黑，多是蓄血。蓄于上，
善忘，时鼻血。蓄于中下，心腹肿痛，如狂，谵语发黄。好酒者，阳明多蓄血。
外感病出现身体发热且有汗，属于伤风；若无汗，则属于伤寒。盗汗（睡眠中出汗），是邪气初传阳明经的表现，也是阳气入内扰动阴分的表现。
自汗（清醒时自然出汗），是阳明经邪气实盛的表现（手足心、腋下均出汗），也是表虚不固的表现。自汗若伴有熟睡打鼾，属于风温。服药后若能出汗，表证应当解除；若未解除，说明发汗不彻底。（必须汗出至足部才算是彻底）。头部有汗而身体无汗，如果小便不利、发热口渴，则会发黄。如果小便利而大便色黑，则是瘀血。如果出现胸满、咳嗽气喘，则是水气病。大抵上，阳明实热不得发散的情况较多。头汗多是可以使用下法的证候。关格证，小便不通，头部出汗的预后不良，主死。额头及手足出冷汗的，属于阴毒证。汗出过多会导致津液脱失而亡阳。凡是热汗必然黏涩（因为肌肉发热而涩滞），冷汗必然滑润（因为肌肉寒冷而滑润）。汗味淡而不咸，淋漓不断不止的，称为绝汗，主死。心之液为汗，肝之液为泪，肺之液为涕，脾之液为涎，肾之液为唾。诊治妇人疾病必须询问月经情况，如果月经适来或适断，此时患病发热，是热邪陷入血室，名叫“热入血室”。其症状表现为胸胁下满闷，白天神志清楚，夜间则胡言乱语，如同见到鬼怪一样。呕吐出血，都源自胃。如果是倾盆而出且成块状，或者颜色紫黑（这是瘀血），或者颜色鲜红（这是新血），这是太冲脉、肾经（这两条经脉合行）、肝经的血，随着胃气一起涌出的。（因为雷火之势猛烈，所以出血量大）。如果只是吐出几口，或者持续一两个时辰，或者颜色红、紫、黑都有，这是胃经本身的血自行溢出。（胃虽然多血，但其热势不像雷火那样猛烈，所以出血量相对较少）。咳血，是因为咳嗽而出，痰中带血丝或血点，这是热邪损伤肺络所致。肺中血液较少，即使少量出血，也恐怕导致肺枯难治。另外，肺病日久会波及肾脏，肾与冲脉并行出入，血从肾和冲脉随咳嗽而出的，血量一定很多（肾虽血少，但合冲脉则多，需知此理），其喉部必定发痒，或有声响，或有硬气从下向上冲逆。咯吐唾液中带血，有的是随着气逆火炎而唾出（不用力），有的是随着痰液咯出（用力，痰中有散漫的血迹），这是肺肾之血。上焦的血浮，中焦的血不沉不浮，下焦的血沉，用水测试可以看见。衄血（鼻出血等），详见血门章节。太阳经的血，有的从鼻子流出，其经脉从背上脑部注入鼻窍，如果不发生衄血，就会从其他途径溢出。肠风便鲜血色鲜红，脏毒便血色暗黯。尿血，排尿疼痛的是血淋，不疼痛的是尿血，都与尿液一同排出。如果不与尿液一同排出的，则是从精窍排出的。想漱口但不吞咽，小便利，大便黑，多是蓄血证。蓄血在上焦，容易健忘，时常流鼻血。蓄血在中下焦，心腹肿痛，如狂乱状态，胡言乱语，身黄。喜好饮酒的人，阳明经多蓄血。
Exogenous pathogenic invasion presenting with fever and sweating indicates Wind-Strike (Shangfeng); absence of sweating indicates Cold Damage (Shanghan). Night sweats (Dao Han) indicate the initial transmission of pathogenic factors to the Yangming channel, or yang invading and disturbing yin.
Spontaneous sweating (Zihan) indicates excess of pathogenic factors in the Yangming channel (sweating on palms, soles, and axillae), or deficiency of exterior defense leading to instability. Spontaneous sweating accompanied by deep sleep and snoring indicates Wind-Warmth (Fengwen). After administering medicine, if sweating occurs, the exterior syndrome should resolve; if it does not, the sweating was incomplete (complete sweating must reach the feet). Sweating only on the head without body sweating, combined with difficult urination, fever, and thirst, leads to jaundice. If urination is free but stool is black, it indicates Blood Stasis. If chest fullness, cough, and wheezing occur, it indicates Water-Qi pathology. Generally, cases where Yangming excess-heat cannot vent are common. Head sweating often indicates a pattern suitable for purgation. In Guan-Ge syndrome, if urination is obstructed and head sweating occurs, the prognosis is fatal. Cold sweat on the forehead, hands, and feet indicates Yin-Du toxin. Excessive sweating leads to fluid depletion and collapse of Yang. Hot sweat is necessarily sticky and astringent (due to hot muscles), while cold sweat is slippery (due to cold muscles). Sweat that is tasteless, non-salty, and continuous without stopping is called Jue-Han (Desperate Sweat), indicating death. The Heart manifests as sweat, the Liver as tears, the Lungs as mucus, the Spleen as saliva, and the Kidneys as thick saliva. When treating women, one must inquire about menstruation. If menstruation has just started or just ceased, and fever develops, heat enters the Blood Chamber (Xue Shi), termed "Heat Entering the Blood Chamber." Symptoms include fullness in the hypochondrium and lower abdomen, clarity during the day, and delirium at night resembling seeing ghosts. Vomiting blood originates from the Stomach. If blood pours out like a basin in clots, or is purple-black (Blood Stasis), or bright red (Fresh Blood), it is blood from the Taichong and Kidney channels (which run together) and the Liver channel, emerging via the Stomach due to the violent force of Lei-Huo (Thunder-Fire). If only a few mouthfuls are vomited, or over one to two hours, with colors varying from red to purple or black, it is blood originating directly from the Stomach channel. Although the Stomach holds much blood, its heat is less violent than Thunder-Fire, hence the volume is smaller. Hemoptysis (Ke Xue) results from coughing, with blood strands or spots in sputum, caused by heat damaging Lung collaterals. Since the Lungs hold little blood, even minor bleeding may lead to dryness and incurability. Furthermore, chronic Lung disease affects the Kidneys. The Kidneys and Chong Mai (Penetrating Vessel) share pathways; blood coughed up from these sources is abundant (though Kidney blood is scarce, combining with Chong makes it plentiful). Throat itching, sounds, or hard Qi rushing upward are present. Spitting blood mixed with saliva (Ko Tuo Xue) occurs either with rebellious Qi and flaming fire (without effort) or with phlegm (with effort, showing scattered blood in phlegm); this is blood from the Lungs and Kidneys. Blood in the Upper Jiao floats; in the Middle Jiao, it neither sinks nor floats; in the Lower Jiao, it sinks. This can be verified with water tests. Nu-Xue (epistaxis etc.) is detailed in the Blood section. Blood from the Taiyang channel may exit via the nose, as the channel runs from the back of the head to the nasal cavity; if epistaxis does not occur, it exits elsewhere. Chang-Feng (Intestinal Wind) presents with fresh red blood in stool; Zang-Du (Visceral Toxin) presents with dark blood. Xiao-Xue (Hematuria): painful urination indicates Blood Lin (Dysuria with blood); painless urination indicates Urine Blood; both exit with urine. If blood exits separately from urine, it comes from the Essence Aperture. Desire to rinse the mouth but no desire to swallow, free urination, and black stool indicate Blood Accumulation (Xu Xue). Accumulation in the upper jiao causes forgetfulness and frequent epistaxis. Accumulation in the middle/lower jiao causes heart/abdominal swelling and pain, manic behavior, delirium, and jaundice. Those who enjoy alcohol tend to have Blood Accumulation in the Yangming channel.