主客之气皆能致其疾，下是主气，上是客气。经曰∶木位之主，其泻以酸，其补以辛；厥阴
之客，以辛补之，以酸泻之，以甘缓之。火位之主，其泻以甘，其补以咸；少阴之客，以甘泻之，
以酸软之；少阳之客，以咸补之，以甘泻之，以咸软之。土位之主，其泻以苦，其补以甘；太阴
之客，以甘补之，以苦泻之，以甘缓之。金位之主，其泻以辛，其补以酸；阳明之客，以酸补之，
以辛泻之，以苦缓之。水位之主，其泻以咸，其补以苦；太阳之客，以苦补之，以咸泻之，以苦
坚之，以辛润之。此六气主客之补泻也。客胜则泻客补主，主胜则泻主补客，应随当缓当急以治
之也。而本经又有六气司天在泉淫胜之治法，有司天在泉反胜之治法，有岁运上下所宜药食之治
法。如是不一，各根据疾苦，顺其运令，以药石五味调治之。为工者当明其岁令，察其形证，诊其
脉急，别其阴阳，根据经旨以拯救之，何患疾之不瘥耶？
五运之中，又有必折其郁气，先取化源之法。《玄珠》以为太阳司天，取九月泻水之源；阳
明司天，取六月泻金之源；少阴少阳司天，取三月泻火之源；太阴司天，取五月泻土之源；厥阴
司天，取年前十二月泻木之源，乃用针迎而取之之法也。故曰∶无失天信，无逆气宜；无翼其胜，
无赞其复，是谓主治者，此也。盖用药之制，有法存焉。然病有久新，方有大小、有毒无毒，而
宜其制。此用之大法也。
或者以为岁运太角木旺土衰，迎取之当泻其肝经而益其脾胃。此非通论也。何哉？岂有人人
脏腑皆同者？假如肝元素虚，脾气太盛，遇此太角之运，肝木稍实，脾气得平，方获安和。若便
泻肝补脾，所谓实实虚虚，损不足而益有余，如此而死者，医杀之耳。是不察其误，反害人增疾
尤甚也。何则？天下事物之理，益之则迟，而损之则速。若服一药取其效，则缓而微；若食一发
病之物，俄顷而应。由是观之，成难毁易，可不谨哉！
主气与客气都能导致疾病，下部是主气，上部是客气。《内经》说：木运之主，用酸味来泻，用辛味来补；厥阴风木为客，用辛味来补，用酸味来泻，用甘味来缓急。火运之主，用甘味来泻，用咸味来补；少阴君火为客，用甘味来泻，用酸味来软坚；少阳相火为客，用咸味来补，用甘味来泻，用咸味来软坚。土运之主，用苦味来泻，用甘味来补；太阴湿土为客，用甘味来补，用苦味来泻，用甘味来缓急。金运之主，用辛味来泻，用酸味来补；阳明燥金为客，用酸味来补，用辛味来泻，用苦味来缓急。水运之主，用咸味来泻，用苦味来补；太阳寒水为客，用苦味来补，用咸味来泻，用苦味来坚固，用辛味来润燥。这就是六气主客补泻的原则。客气胜则泻客气、补主气，主气胜则泻主气、补客气，应当根据病情的缓急来治疗。而《内经》中还有六气司天在泉淫胜的治疗方法，有司天在泉反胜的治疗方法，有岁运上下所适宜的药食治疗方法。像这样的方法不止一种，各根据病人的痛苦，顺应其运气时令，用药物和石药及五味来调治。作为医生应当明了当年的运气时令，观察病人的形体症状，诊察脉象的紧急程度，辨别阴阳，依据经典旨意来救治病人，还担心疾病不能痊愈吗？
在五运之中，又有必须折服其郁结之气，先取化源的方法。《玄珠密语》认为太阳司天，取九月泻水之源；阳明司天，取六月泻金之源；少阴、少阳司天，取三月泻火之源；太阴司天，取五月泻土之源；厥阴司天，取前一年十二月泻木之源，这是用针刺迎而取之的方法。所以说：不要违背天时信期，不要逆乱气宜；不要助长其胜气，不要赞助其复气，这就是主治的原则。大概用药的法度，是有规律存在的。然而疾病有久病新病之分，方剂有大方小方之别，有毒药无毒药之异，而适宜其法度。这是用药的大法。
有人以为岁运太角（木旺），木旺则土衰，迎取之时应当泻肝经而补益脾胃。这不是通论。为什么呢？难道人的脏腑都是一样的吗？假如肝元素虚，脾气太盛，遇到这种太角的运程，肝木稍微充实，脾气得以平和，身体才能安和。如果就泻肝补脾，这就叫作“实实虚虚”，损伤不足的正气而增加有余的邪气，像这样死去的，是医生杀死了他啊。这是不考察错误的原因，反而害人性命、加重疾病更为严重啊。为什么呢？天下事物的道理，增益它则迟缓，损害它则迅速。如果服用一剂药取其疗效，则是缓慢而轻微的；如果吃一发病之物，顷刻间就会反应。由此看来，成就难而毁坏易，能不谨慎吗！
Both the principal qi (Zhu Qi, 主气) and the guest qi (Ke Qi, 客气) can cause diseases. The lower part corresponds to the principal qi, and the upper part corresponds to the guest qi. The Classics state: For the principal of Wood, drain with sour [flavor] and tonify with pungent [flavor]; for the guest of Jueyin (Liver/Gallbladder channel), tonify with pungent, drain with sour, and moderate/spasmolyze with sweet. For the principal of Fire, drain with sweet and tonify with salty; for the guest of Shaoyin (Heart/Kidney channel), drain with sweet and soften/harden-resolve with sour; for the guest of Shaoyang (Sanjiao/Gallbladder channel), tonify with salty, drain with sweet, and soften/harden-resolve with salty. For the principal of Earth, drain with bitter and tonify with sweet; for the guest of Taiyin (Spleen/Stomach channel), tonify with sweet, drain with bitter, and moderate/spasmolyze with sweet. For the principal of Metal, drain with pungent and tonify with sour; for the guest of Yangming (Large Intestine/Stomach channel), tonify with sour, drain with pungent, and moderate/spasmolyze with bitter. For the principal of Water, drain with salty and tonify with bitter; for the guest of Taiyang (Bladder/Kidney channel), tonify with bitter, drain with salty, fortify/strengthen with bitter, and moisten/lubricate with pungent. These are the principles of tonifying and draining regarding the principal and guest qi of the Six Qi (Liu Qi, 六气). When the guest qi prevails, drain the guest and tonify the principal; when the principal qi prevails, drain the principal and tonify the guest. Treatment should follow the urgency or slackness of the condition. Furthermore, the original Classics contain treatment methods for excessive influence (Yin Sheng, 淫胜) of the Six Qi during Si Tian (Si Tian, 司天 - ruling qi of the upper heaven) and Zai Quan (Zai Quan, 在泉 - ruling qi of the lower spring), methods for reverse prevailing conditions, and methods for appropriate medicines and foods based on the annual movement (Sui Yun, 岁运) above and below. There are numerous such methods; each should be applied according to the patient's suffering, following the seasonal movements and commands, using medicinal stones and the five flavors for regulation. A skilled practitioner must understand the annual seasonal commands, observe the physical signs and symptoms, diagnose the pulse for urgency, distinguish Yin and Yang, and rescue patients according to the canonical principles. How could one worry that the disease will not heal?
Among the Five Movements (Wu Yun, 五运), there is also a method of necessarily breaking the stagnant qi by first extracting the source of transformation (Hua Yuan, 化源). *Xuanzhu* states that when Taiyang rules, extract in the ninth month to drain the source of Water; when Yangming rules, extract in the sixth month to drain the source of Metal; when Shaoyin and Shaoyang rule, extract in the third month to drain the source of Fire; when Taiyin rules, extract in the fifth month to drain the source of Earth; when Jueyin rules, extract in the twelfth month of the previous year to drain the source of Wood. This is the method of using acupuncture to intercept and extract. Therefore it is said: Do not lose faith in the heavenly timing, do not go against the appropriateness of the qi; do not assist its dominance, do not praise its retaliation. This is what is meant by the principle of primary treatment. Generally, the formulation of medicine has established laws. However, diseases differ in duration (old vs. new), formulas vary in size (large vs. small), and substances vary in toxicity (toxic vs. non-toxic), all requiring appropriate regulation. This is the great principle of using medicine.
Some argue that when the annual movement is Tai Jue (excessive Wood leading to strong Wood and weak Earth), one should intercept this by draining the Liver Channel (Gan Jing, 肝经) and benefiting the Spleen and Stomach. This is not a universal theory. Why? Are the internal organs of everyone identical? Suppose the Liver element is deficient and the Spleen Qi is excessive. Encountering this Tai Jue movement, if the Liver Wood becomes slightly substantial, the Spleen Qi may become balanced, and the body achieves harmony. If one were to drain the Liver and tonify the Spleen in this case, it would be described as "making the excess more excess and the deficiency more deficient" (Shi Shi Xu Xu, 实实虚虚), damaging what is insufficient and augmenting what is already surplus. Those who die in such cases are killed by the physician. This failure to examine the error results in harming people and aggravating the disease even further. Why is this? The principle of things in the world is that adding to them makes the effect slow, while removing from them makes the effect rapid. If one takes a medicine to achieve an effect, the change is slow and subtle; if one consumes something that triggers a disease, the reaction occurs almost instantly. From this perspective, building up health is difficult while destroying it is easy. Can one not be cautious?