伤寒一日。足太阳受病。太阳者。膀胱之经也。为三阳之首。故受病。其脉络于腰脊。
主于头项。故得病一日。头项腰脊痛也。伤寒二日。足阳明受病。阳明者。胃之经也。主于
肌肉。其脉络于鼻。入于目。故得病二日。内热鼻干。不得眠也。诸阳在表。表始受病在皮
肤之间。故可摩膏、火灸、发汗而愈也。凡五脏不和。六腑不通。营卫不行。如是之后。
三日乃死。何也。夫足阳明者。胃之脉也。十二经之长也。其气血盛。故不通。三日其气乃
尽。故死尔。其未满三日者。可汗而已。其满三日者。可下而已也。伤寒三日。足少阳受病
。少阳者。胆之经也。其脉循于胁。上于颈耳。故得病三日。胸胁热而耳聋也。三阳经络。
始相传病。未入于脏。可汗而解也。伤寒四日。足太阴受病。太阴者。脾之经也。为三阴之
首。是故三日以后。阳受病讫。传之于阴。而太阴受病焉。其脉络于脾。主于喉嗌。故得病
四日。腹满而嗌干。其病在胸膈。故可吐而愈也。伤寒五日。足少阴受病。少阴者。肾之经
也。其经贯肾络肺。系于舌。故得病五日。口燥舌干。渴而引水也。其病在肠。故可下而愈
也。伤寒六日。足厥阴受病。厥阴者。肝之经也。其脉循阴络于肝。故得病六日。烦满而阴
缩也。此则阴阳俱受病。毒瓦斯在胃。可下而愈也。七日太阳病衰。头痛小愈。又伤寒七日。
病法当小愈。阴阳诸经传病终故也。今七日以后。病反甚者。欲为再经病也。再经病者。经
络重受病也。伤寒八日。阳明病衰。身热小愈。又八日不解者。或者诸阴阳经络。重受于病
。或因发汗吐下之后。毒瓦斯未尽。所以病证犹在也。伤寒九日。少阳病衰。耳聋微闻。又伤
寒九日以上。病不除者。或初一经受病者。不能相传。或已传三阳讫。而不能传于阴。致停
滞累日。病证不解。故日数多。而病候改变也。伤寒十日。太阴病衰。腹胃如故。则思欲饮
食。伤寒十一日。少阴病衰。渴止不烦满。舌干已也。伤寒十二日。厥阴病衰。囊少纵。腹
微下。毒瓦斯皆去。病日已矣。
On the first day of *Shanghan* (Cold Damage), the Foot-Taiyang channel is affected. The Taiyang channel belongs to the Bladder, and is the head of the three Yang channels; therefore, upon being affected, its collaterals connect to the lumbar spine, and it governs the head and neck. Thus, on the first day of illness, there is pain in the head, neck, lumbar region, and spine.
On the second day, the Foot-Yangming channel is affected. The Yangming channel belongs to the Stomach, governs the muscles, and its collaterals connect to the nose and enter the eyes. Thus, on the second day of illness, there is internal heat, dryness of the nose, and inability to sleep.
All Yang channels are located at the exterior. When the exterior is initially affected, the pathogen resides between the skin and hair; thus, it can be cured by applying medicated oils, moxibustion, or inducing sweating. If the Five Zang organs are disordered, the Six Fu organs are obstructed, and the Ying (Nutritive) and Wei (Defensive) Qi fail to circulate properly, death will occur after three days. Why? Because the Foot-Yangming channel is the channel of the Stomach and the leader of the twelve channels; its Qi and Blood are abundant. If obstruction occurs here, it takes three days for this Qi to exhaust, leading to death. For illnesses not yet reaching three days, treatment by sweating is appropriate; for illnesses exceeding three days, treatment by purgation is appropriate.
On the third day, the Foot-Shaoyang channel is affected. The Shaoyang channel belongs to the Gallbladder, and its vessel courses along the hypochondrium, ascending to the neck and ears. Thus, on the third day of illness, there is heat in the chest and hypochondrium, and deafness. The meridians of the three Yang channels begin to transmit the disease among themselves, but the pathogen has not yet entered the Zang organs; it can be resolved by inducing sweating.
On the fourth day, the Foot-Taiyin channel is affected. The Taiyin channel belongs to the Spleen and is the head of the three Yin channels. Therefore, after the third day, when the Yang channels have finished receiving the pathogen, it transmits to the Yin channels, affecting the Taiyin. Its collaterals connect to the Spleen, and it governs the throat. Thus, on the fourth day of illness, there is abdominal fullness and dryness of the throat. Since the disease is located in the chest and diaphragm, it can be cured by emesis.
On the fifth day, the Foot-Shaoyin channel is affected. The Shaoyin channel belongs to the Kidney; its vessel passes through the Kidney, connects to the Lung, and attaches to the tongue. Thus, on the fifth day of illness, there is dryness of the mouth and tongue, thirst, and a desire to drink water. Since the disease is located in the intestines, it can be cured by purgation.
On the sixth day, the Foot-Jueyin channel is affected. The Jueyin channel belongs to the Liver; its vessel courses along the Yin collaterals to connect with the Liver. Thus, on the sixth day of illness, there is vexation, abdominal fullness, and retraction of the genitals. At this point, both Yin and Yang channels are affected, and toxic heat resides in the Stomach; it can be cured by purgation.
On the seventh day, the Taiyang disease begins to recede, and the headache slightly improves. According to the laws of *Shanghan*, the condition should slightly improve on the seventh day because the transmission of disease through the Yin and Yang channels has reached its conclusion. If, however, the condition worsens after the seventh day, it indicates a "Re-channel Disease" (*Zai Jing Bing*), where the meridians receive the pathogen again.
On the eighth day, the Yangming disease begins to recede, and body heat slightly improves. If the disease persists beyond eight days, it may be due to the various Yin and Yang meridians receiving the pathogen again, or because toxic heat remains incomplete after previous treatments with sweating, emesis, or purgation, hence the symptoms persist.
On the ninth day, the Shaoyang disease begins to recede, and deafness slightly improves, allowing for faint hearing. If the disease persists beyond nine days without resolution, it may be because the initial channel affected could not transmit further, or because having completed transmission through the three Yang channels, it failed to transmit to the Yin, causing stagnation for several days. Consequently, the number of days increases, and the clinical manifestations change.
On the tenth day, the Taiyin disease begins to recede; the abdomen and stomach return to normal, and the patient desires food and drink.
On the eleventh day, the Shaoyin disease begins to recede; thirst ceases, vexation and fullness disappear, and dryness of the tongue resolves.
On the twelfth day, the Jueyin disease begins to recede; the scrotum relaxes slightly, the abdomen becomes soft, toxic heat is eliminated, and the illness is nearing completion.