治阴毒瓦斯攻上腹痛，四肢逆冷恶候。
川乌头去皮脐，冷水浸七日后，薄切曝干，纸袋盛。遇有患者，取为细末一大钱，盐一小钱，水一盏半
，煎至七分，通口服。压下阴毒，所便后如猪血相似。未已，良久再服之。
治阴毒面色青，四肢逆冷，心躁腹痛。
硫黄（为末）
上用新汲水调二钱，良久或寒一起，或热一起便看紧慢，汗出瘥。
有人患伤寒六七日，心烦昏睡多吐，小便白色自汗。予诊之，寸口尺中俱紧。予曰
寒中少阴之经，是以脉紧。仲景云∶病患脉紧而汗出者，亡阳也。属少阴，法当咽痛而复下
利，盖谓此也。或曰∶脉紧属七表，仲景紧脉属少阴，紧脉属阳邪属阴邪？予曰∶仲景脉寸
口俱紧者，清邪中于上焦，浊邪中于下焦。又云∶阴阳俱紧者，口中气出，唇口干燥，倦卧
足冷，鼻中涕出，舌上滑胎，勿妄治也。又云∶紧则为寒。又云∶诸紧为寒。又云∶或难曰
紧脉从何而来？师曰∶假令已汗若吐，以肺里寒，故令脉紧；假令咳，坐饮冷水，故令脉紧
；假令下利胃虚，故令脉紧。又曰∶寸口脉微，尺脉微，尺脉紧，其人虚损多汗。由是观之
，则是寒邪之气，入人经络所致，毕虚寒之脉也。其在阳经则浮而紧；在阴经则沉而紧。故仲
景云∶浮紧者名为伤寒。又曰∶阳明脉浮而紧者，必潮热。此在阳则浮而紧也。在阴则沉而
紧，故仲景云∶寸口脉微，尺脉紧，至七八日自下利，脉暴微，手足反温，脉紧反出去者，
此欲解也。此在阴则沉而紧也。仲景云∶浮为在表，沉为在里；数为在腑，迟为在脏。欲知
表里脏腑，先以浮沉迟数为定，然后兼于脉而别阴阳也。故论伤寒，当以仲景脉法为准。伤
寒之必本仲景，犹兵家之必本孙吴也。舍是而之他者，是犹舍规矩而求方圆，舍律吕而正五
音，可乎？
《活人》丹砂丸论阴阳二毒相伏，破阴只是伏阳一脉，阴中伏阳，脉即翕奄沉也。
治疗阴毒邪气上攻导致的腹痛，以及四肢厥冷等危重证候。
取川乌头，去除皮和脐部，用冷水浸泡七日后，切成薄片晒干，装入纸袋保存。遇到患者时，取细末一钱（约3-5克），盐一小钱，加水一盏半，煎煮至七分满，一次性温服。此药能压制阴毒，服药后大便排出物状如猪血相似。若症状未止，隔一段时间后再次服用。
治疗阴毒导致的面色发青，四肢厥冷，心中烦躁且腹痛。
取硫黄（研为细末）。
以上述新汲取的井水调服二钱，过一段时间观察病情变化，若出现寒战或发热，随即查看脉象的紧缓程度，待汗出则病愈。
有人患伤寒六七日，心烦意乱、昏睡多吐，小便颜色清白，自汗出。我诊察其脉，寸口和尺中脉象均呈现紧象。我说：这是寒邪侵入少阴经所致，因此脉象紧。张仲景说：病人脉紧而汗出的，是亡阳的表现。这属于少阴病，按理应出现咽痛并伴有下利，说的就是这种情况。有人问：脉紧通常归属于“七表”脉（阳脉），但张仲景认为紧脉属少阴，那么紧脉究竟是属阳邪还是属阴邪？我说：张仲景指出，寸口脉俱紧的，是清邪侵犯上焦，浊邪侵犯下焦。又说：阴阳脉俱紧的，表现为口中呼气热、唇口干燥、倦怠嗜卧、足冷、鼻流清涕、舌面滑润，此时不可妄加治疗。又说：紧脉主寒。又说：各种紧脉皆主寒。又说：或者有人问紧脉从何而来？老师说：假如已经发汗或催吐，因肺中有寒，所以令脉紧；假如咳嗽，因为饮用了冷水，所以令脉紧；假如下利，因为胃气虚弱，所以令脉紧。又说：寸口脉微，尺脉微，尺脉紧，其人虚损且多汗。由此看来，这是寒邪之气侵入人体经络所致，是典型的虚寒脉象。如果是在阳经，则脉浮而紧；如果是在阴经，则脉沉而紧。所以张仲景说：浮紧脉名为伤寒。又说：阳明经脉浮而紧的，必定有潮热。这是在阳经的情况，即浮而紧。在阴经则是沉而紧，所以张仲景说：寸口脉微，尺脉紧，到了七八天自然下利，脉突然变微，手足反而温暖，脉紧象反而消退的，这是病欲解除的表现。这是在阴经的情况，即沉而紧。张仲景说：浮脉主表，沉脉主里；数脉主腑，迟脉主脏。想要知道表里脏腑，先以浮、沉、迟、数来确定，然后再结合脉象来辨别阴阳。所以论述伤寒，应当以张仲景的脉法为准绳。研究伤寒必须依据张仲景，就像兵家必须依据孙武和吴起一样。舍弃这些而追求其他方法，就如同舍弃圆规和曲尺去求方圆，舍弃音律去校正五音，可以吗？
《活人书》中的丹砂丸论述了阴阳二毒相互潜伏，破除阴毒只是伏藏于阴中的阳脉，阴中伏阳，脉象表现为忽隐忽现的沉脉（翕奄沉）。
Treats severe conditions where Yin-toxic pathogenic factors attack upward, causing abdominal pain and cold extremities (limb reversal).
Take Chuanwu Tou (Aconiti Radix Preparata), remove the skin and navel, soak in cold water for seven days, slice thinly, dry in the sun, and store in a paper bag. When treating a patient, take one qian (approx. 3-5g) of the fine powder, one small qian of salt, add one and a half lamps of water, decoct until reduced to seven-tenths, and administer orally in one dose. This suppresses the Yin-toxin; after defecation, the stool resembles pig's blood. If symptoms persist, administer again after a while.
Treats Yin-toxin presenting with a bluish complexion, cold extremities, mental restlessness, and abdominal pain.
Take Shihuang (Sulfur), prepared as a fine powder.
Mix two qian with fresh well water, wait for a while, or observe if chills or fever arise, then check the pulse for tightness or slackness; recovery occurs when sweating ensues.
A person suffered from Shanghan (Cold Damage) for six or seven days, experiencing mental irritability, drowsiness, frequent vomiting, white urine, and spontaneous sweating. Upon diagnosis, both the Cun (inch) and Chi (cubit) positions of the pulse were tight. I stated: "This is Cold invading the Shaoyin meridian, hence the tight pulse." Zhang Zhongjing said: "When a patient has a tight pulse and sweats, it indicates the loss of Yang Qi (Wangyang)." This belongs to Shaoyin disease; according to the method, it should present with sore throat and diarrhea, which refers to this case. Someone asked: "The tight pulse usually belongs to the 'Seven Superficial Pulses' (Yang pulses), but Zhang Zhongjing associates the tight pulse with Shaoyin. Does the tight pulse belong to Yang pathogens or Yin pathogens?" I replied: "Zhang Zhongjing states that when both Cun and Kou positions are tight, clear pathogens attack the Upper Jiao, and turbid pathogens attack the Lower Jiao. He also said: 'When both Yin and Yang pulses are tight,' symptoms include warm breath from the mouth, dry lips and tongue, fatigue and desire to lie down, cold feet, nasal discharge, and a slippery coating on the tongue; do not treat rashly. He further said: 'Tightness indicates Cold.' And: 'All tight pulses indicate Cold.' Or someone might ask: 'Where does the tight pulse come from?' The Master said: 'If sweating or vomiting has already occurred, due to Cold in the Lung interior, the pulse becomes tight; if coughing occurs because cold water was drunk, the pulse becomes tight; if diarrhea occurs due to Stomach deficiency, the pulse becomes tight.' He also said: 'If the Cun pulse is faint, the Chi pulse is faint, and the Chi pulse is tight, the person suffers from deficiency and excessive sweating.' From this, we see that this is caused by Cold pathogenic qi entering the meridians and collaterals, representing a typical deficiency-cold pulse. If located in Yang meridians, the pulse is floating and tight; if in Yin meridians, the pulse is deep and tight. Thus, Zhang Zhongjing said: 'Floating and tight is named Shanghan.' He also said: 'If the Yangming pulse is floating and tight, tidal fever must occur.' This is the case in Yang, i.e., floating and tight. In Yin, it is deep and tight, so Zhang Zhongjing said: 'If the Cun pulse is faint, the Chi pulse is tight, and after seven or eight days spontaneous diarrhea occurs, the pulse suddenly becomes faint, hands and feet become warm, and the tightness disappears, this indicates the disease is resolving.' This is the case in Yin, i.e., deep and tight. Zhang Zhongjing said: 'Floating indicates exterior, deep indicates interior; rapid indicates Fu organs, slow indicates Zang organs.' To determine interior/exterior and Zang/Fu, first establish based on floating, deep, rapid, and slow, then differentiate Yin and Yang by combining with other pulse characteristics. Therefore, when discussing Shanghan, one must take Zhang Zhongjing's pulse methodology as the standard. Studying Shanghan must be based on Zhang Zhongjing, just as military strategy must be based on Sun Wu and Wu Qi. To abandon this for others is like abandoning compasses and squares to seek perfect shapes, or abandoning musical pitches to tune the five tones; is this acceptable?
The Dansha Wan (Cinnabar Pill) in Huoren (The Living Manual) discusses the mutual entrapment of Yin and Yang toxins. Breaking the Yin toxin merely reveals the Yang pulse hidden within; Yin-hidden-Yang presents as a pulse that appears and disappears deeply (Xi Yan Chen).