既知四时之色。须知四时之病。知四时之病。以察四时之色。夫而后可按四时之色。以言四时之病。其病
维何。玉机真藏论曰。春脉如弦。太过则令人善忘。忽忽眩冒而巅疾。其不及则令人胸痛。引背下则两胁
满。夏脉如钩。太过则令人身热。而肤痛为浸淫。其不及则令人烦心。上见咳唾。下为气泄。秋脉如浮。太
过则令人逆气而背痛愠愠然。其不及则令人喘。呼吸少气而咳。上气见血。下闻病音。冬脉如营。太过则
令人解 。脊脉痛而少气不欲言。其不及。则令人心悬如病饥。 中清。脊中痛。少腹满。小便变。脾脉者。中
央土。孤脏以灌四旁者也。太过则令人四肢不举。其不及则令人九窍不通。名曰重强。此皆四时之病也。
然此四时之病。内经以脉言。而吾以色言者何哉。盖尝读内经而有悟于岐黄之言焉。岐伯曰。夫色脉与
尺脉之相应也。如桴鼓影响之相应也。不得相失也。色之变化。以应四时之脉。此上帝之所贵。以合于神
明也。黄帝曰。吾得脉之大要。天下至数。五色脉变。揆度奇恒。道在于一。由此观之。四时气色之生克。亦可
以脏腑经脉之病症比例而推矣。何也。五脏之病。四时之色。推之以五行之理。太过则薄所胜。而乘所不
胜。其不及则所胜妄行。而所生受病。所不胜薄之也。设或知病而不知诊。或知诊而不知病。则虽能知诊。
虽能知病。而究不知诊病。即能知诊病。而尚不知治病。而况尚不知诊。尚不知病耶。呜呼。灵素之书。若此
其详也。延医之法。若此其备也。然而无有乎尔。则亦无有乎尔。（善忘之忘。宋林亿等较正千金素问。皆云
当作怒。今考素问气交变大论。亦作怒。宜从之。）
既然了解了四季对应的面色，就必须知晓四季常见的疾病。了解四季的疾病，是为了通过观察四季的面色来验证病情。只有做到这一点，才能依据四季的面色来推断四季的疾病。这些疾病具体是什么呢？《素问·玉机真藏论》说：春季的脉象像琴弦一样柔和而长。如果脉气太过，就会使人容易健忘，时常感到头晕目眩甚至头部患病；如果脉气不及，就会使人胸痛，牵引至背部，下部则感觉两胁胀满。夏季的脉象像钩子一样来盛去衰。如果脉气太过，就会使人身体发热，皮肤疼痛并发生浸淫疮（一种蔓延性的皮肤病）；如果脉气不及，就会使人心中烦闷，上部出现咳嗽吐痰的症状，下部出现气泄（如二便失禁或气短下陷）的症状。秋季的脉象像浮毛一样轻虚。如果脉气太过，就会使人气逆上冲且背部隐隐作痛；如果脉气不及，就会使人喘息，呼吸短促并伴有咳嗽，上部可见咳血，下部可听到病变的声音（如肠鸣等）。冬季的脉象像营垒一样沉实有力。如果脉气太过，就会使人肢体懈怠无力，脊柱疼痛且气短不想说话；如果脉气不及，就会使人心里空虚得像得了饥饿病一样，胃脘部清冷，脊柱中间疼痛，小腹胀满，小便异常。脾脏的脉象对应中央的土行，是单独滋养四方（其他四脏）的脏器。如果脾气太过，就会使人四肢无法抬起；如果脾气不及，就会使人九窍不通畅，这种病症称为“重强”（身体沉重僵硬）。以上这些都是四季相关的疾病。然而，《内经》中上述内容是从脉象角度论述的，而我这里从面色角度论述的原因是什么呢？我曾经研读《内经》，从中领悟到了岐伯和黄帝的言论。岐伯说：面色、脉象与尺肤诊察的结果相互对应，就像鼓槌敲击鼓面、影子跟随物体、回声响应声音一样，不能有所偏差。面色的变化，应当与四季的脉象相应，这是上天所重视的，用以契合神明的规律。黄帝说：我掌握了脉诊的要领，这是天下最根本的道理。五色与脉象的变化，通过揆度（衡量比较）奇恒（正常与异常），其道理在于一个统一的整体。由此看来，四季气色的生克关系，也可以参照脏腑经脉的病症进行类推。为什么呢？五脏的疾病和四季的面色，可以用五行之理来推演。脉气太过，就会克制它所胜行的季节/脏器，而欺凌它不胜行的季节/脏器；脉气不及，就是它所胜行的季节/脏器妄自行事，而它所生的季节/脏器受病，同时受到它所不胜行的季节/脏器的克制。假使知道疾病却不知道诊察方法，或者知道诊察方法却不知道疾病本质，那么虽然能知道诊察，虽然能知道疾病，但终究还是不懂如何诊病；即使能懂诊病，还不懂得治疗疾病，更何况连诊察和疾病都不懂呢？唉，《灵枢》和《素问》这两本书，讲解得如此详细。诊治医生的法则，准备得如此完备。然而，现在却找不到这样的人了，也就找不到这样的人了。（关于“善忘”的“忘”字，宋代林亿等人校订《千金方》和《素问》时，都说是当作“怒”字。如今考证《素问·气交变大论》，也写作“怒”，应该遵从这一说法。）
Having understood the complexions corresponding to the four seasons, one must also understand the diseases prevalent in the four seasons. Understanding the diseases of the four seasons allows one to examine the complexions of the four seasons. Only then can one speak of the diseases of the four seasons by observing their complexions. What are these diseases? The *Jade Machine True Viscera Discourse* (Yùjī Zhēnzàng Lùn) states: The pulse of Spring is like a string (xián). If excessive, it causes forgetfulness, dizziness, and vertigo, leading to disorders at the vertex (diān jí). If deficient, it causes chest pain radiating to the back, and below, fullness in both hypochondria. The pulse of Summer is like a hook (gōu). If excessive, it causes feverish sensation in the body and skin pain manifesting as spreading sores (jìnyín). If deficient, it causes vexation in the heart, with coughing and expectoration appearing above, and qi leakage (qì xiè) below. The pulse of Autumn is like floating (fú). If excessive, it causes rebellious qi and dull back pain. If deficient, it causes panting, shortness of breath, and coughing, with blood appearing from above (hemoptysis) and pathological sounds heard below. The pulse of Winter is like a camp (yíng), meaning deep and firm. If excessive, it causes flaccidity of the limbs, pain in the spinal vessels, shortness of breath, and reluctance to speak. If deficient, it causes a feeling of emptiness in the heart as if hungry, coldness in the epigastrium, pain in the middle of the spine, fullness of the lower abdomen, and abnormal urination. The Spleen pulse corresponds to Earth in the Center; it is the solitary viscera that nourishes the four peripheries. If excessive, it causes inability to lift the limbs. If deficient, it causes obstruction of the nine orifices, a condition named "heavy stiffness" (zhòng qiáng). These are all the diseases related to the four seasons. However, the *Nei Jing* discusses these four-season diseases in terms of pulses, whereas I discuss them in terms of complexion. Why is this? Having studied the *Nei Jing*, I have gained insight into the words of Qibo and Huangdi. Qibo said: The correspondence between complexion, pulse, and Cun-Che-Fu (radial artery palpation) is like the striking of a drum with a drumstick, the shadow following the object, and the echo responding to the sound; they cannot be inconsistent. Changes in complexion should correspond to the pulses of the four seasons. This is highly valued by Heaven, aligning with divine illumination. Huangdi said: I have grasped the essentials of pulse diagnosis, which is the greatest principle under heaven. The changes of the five colors and pulses, measured by Kuidu (comparing normal and abnormal), lie in unity. From this perspective, the generation and restriction among the qi and complexions of the four seasons can be inferred by analogy with the pathological conditions of the zang-fu organs and meridians. Why? The diseases of the five zang organs and the complexions of the four seasons can be deduced using the principles of the Five Elements. Excess leads to attacking what it overcomes and bullying what it cannot overcome; deficiency leads to what it overcomes acting recklessly, what it generates suffering disease, and what cannot overcome it encroaching upon it. If one knows the disease but not the diagnostic methods, or knows the diagnostic methods but not the disease, then although one may know diagnostics and disease, one ultimately does not know how to diagnose illness. Even if one knows how to diagnose illness, one still does not know how to treat it, let alone knowing diagnostics and disease. Alas, the books of *Lingshu* and *Suwen* are so detailed. The methods for engaging physicians are so comprehensive. Yet, there is none; indeed, there is none. (Note: Regarding "forgetfulness" (wàng), Song dynasty scholar Lin Yi and others corrected the *Qianjin Suwen*, stating it should be read as "anger" (nù). Current examination of the *Suwen · Qi Jiao Bian Da Lun* also writes "anger," so this reading should be followed.)