夫人果能顺六气之和，平七情之戾，使 疾不作，岂不
甚善。然疾者，至圣之所慎，惟明哲之人不治已病治未病，既病而需医药，犹临渴而掘井泉，鲜有能
济者。况良医难逢，真药莫辨，尝见死于病者十之三，死于医者十之七。盖医之一道，须上知天文，
下知地理，中知人事，三者俱明，然后可以语人之疾病。不然，则如无目夜游，无足昼蹑，动致颠仆，
而欲愈人之疾者，未之有也。至药之为用，或道地不真，美恶迥别，或市肆多伪，气味全乖，非惟不能
中病，反致病增。用者不察，尝试漫施，则下咽不返，死生立判，顾不大可惧耶。所以有服药者之多
毙，不药者之反存。岁庚寅，予补选都门。适同宗前辈某，亦候补郡守，侨寓悯忠寺，抱 二年，坚忍
不服药，惟调息饮食起居。病无减退，亦未加剧。会密友某至京，诣悯忠寺视疾，力荐良医一人，极称
其治病如神。前辈某因怂恿难却，强就延医。密友代为购药，意倍殷勤，且决其旦夕奏效。前辈佯诺之。
药虽煎，未沾唇也。越日密友亦病，并非沉 ，即所荐之良医药之。前辈日使家仆问讯，盖答其前意之殷
勤也。甫数日，仆忽返告曰∶密友某死矣。前辈惋叹不已。未几已病全愈，得补官出都矣。又，族叔陶
村公宰来阳，长子婴风寒疾，诸医治莫效。访求一良医，进药数剂，病转甚，势危笃。医来，病者坚拒
之。医大言嚷曰∶药力不胜病，如再服无效，予甘罪罚。族叔且疑且信，强其子下咽。无何痰起，而气旋
绝矣。急索良医，已逃窜无踪。噫，可畏哉。举书籍所传，庸医杀人，不可殚述，此则予所耳而目之者。
或者曰∶然则医药固可废乎？曰∶何可废也，慎之已尔。慎医药莫如慎疾病，慎疾病尤宜知疾病。今为就
一身五脏受病之因、辨病之误、免病之诀，分类指示。据病之种类数百，止就所常见而易构者摘录之。俾
于未病之先，知所谨惧，庶几不借神楼而普登春台也。
按东垣《格致余论·序》谓∶故方新病，安有能相值者，泥之且杀人。此编中载病不载方，
即此意也。
人如果能够顺应六气（风、寒、暑、湿、燥、火）的和谐，平息七情（喜、怒、忧、思、悲、恐、惊）的乖戾，使疾病不产生，这难道不是很好的事吗？然而疾病是至圣之人所谨慎对待的，只有明智的人才会“治未病”（在疾病发生之前进行预防），等到已经生病才需要医药，就像临到口渴了才去挖井，很少能够救急的。况且良医难遇，真药难辨，我曾见到死于疾病的占十分之三，死于庸医误治的占十分之七。大概医学这一道，必须上通天文，下知地理，中晓人事，这三方面都明白了，然后才可以谈论人的疾病。否则，就如同没有眼睛在夜间行走，没有脚在白天走路，动不动就会跌倒摔伤，想要治愈别人的疾病，是不可能的。至于药物的作用，有的产地不正宗，好坏差别很大；有的市场上假货多，气味完全违背药性，不仅不能对症治病，反而会使病情加重。使用者不加考察，随意尝试施用，那么药一下咽就无法挽回，生死立刻判定，这难道不值得恐惧吗？所以有服药的人大多死亡，不服药的人反而存活。
岁庚寅年，我补选为京城官员。恰逢同宗前辈某人，也在候补郡守之列，寄住在悯忠寺，患有两年的痼疾，坚忍不拔地不服药，只是调理呼吸、饮食和起居。病情没有减退，也没有加剧。恰逢密友某人到京城，到悯忠寺探望病情，极力推荐一位良医，极口称赞他治病如神。前辈某人因为难以推辞，勉强延请医生。密友代为购买药物，情意加倍殷勤，并且断定药到病除。前辈假装答应。药虽然煎好了，但还没有沾嘴唇。第二天密友也病了，并不是重病，就用那位推荐的良医的药来治疗。前辈每天派家仆去问候，大概是回答他之前那份殷勤的情意。才过了几天，仆人忽然回来报告说：密友某人死亡了。前辈惋惜叹息不已。不久后自己的病全愈，得以补官离开京城了。
又有一次，族叔陶村公宰任来阳县令，长子感染了风寒疾病，众多医生治疗都没有效果。访求一位良医，进药几剂，病情反而加重，形势危急。医生来了，病人坚决拒绝服用。医生大声嚷嚷说：“药力抵不过病邪，如果再服用无效，我甘愿受罚。”族叔半信半疑，强迫儿子吞下药。不一会儿痰涌起，气息随即断绝了。急忙寻找良医，已经逃窜得无影无踪。唉，真是可怕啊。列举书籍中所传的，庸医杀人的事例，不可尽述，这些都是我亲眼所见、亲耳所闻的。
有人问：那么医药就可以废弃了吗？回答说：怎么可以废弃呢，只是要谨慎罢了。谨慎医药不如谨慎疾病，谨慎疾病尤其应该了解疾病。现在我就针对一身五脏受病的成因、辨别疾病的错误、避免疾病的诀窍，分类指示。根据疾病的种类数百种，只摘录那些常见且容易患上的。使得人们在未病之前，知道谨慎畏惧，或许就不必借助神楼（指医院或药房）而能普遍登上春台（指健康长寿的境界）了。
按东垣《格致余论·序》中说：所以方剂和疾病，哪有能完全对应的，拘泥于方子反而会杀人。本编中记载疾病而不记载方剂，就是这个意思。
If a person can indeed follow the harmony of the Six Qi (Wind, Cold, Summer-heat, Dampness, Dryness, Fire) and level the aberration of the Seven Emotions (Joy, Anger, Worry, Thought, Sorrow, Fear, Fright), thereby preventing disease from arising, would this not be excellent? However, disease is something that even the Sage treats with caution. Only the wise practice "treating undiseased states" (preventing disease before it occurs). Waiting until one is already ill to seek medicine is like digging a well only when one is thirsty; few will succeed in saving themselves. Moreover, good physicians are hard to find, and genuine medicines are difficult to identify. I have seen three out of ten die from their diseases, while seven out of ten die from medical malpractice. The art of medicine requires knowing astronomy above, geography below, and human affairs in between. Only when these three aspects are clearly understood can one discuss human diseases. Otherwise, it is like wandering at night without eyes or walking by day without feet; one will inevitably stumble and fall. It is impossible to cure others' diseases under such conditions.
Regarding the use of medicines, some may not be from authentic origins, leading to vast differences in quality between good and bad. Others may be counterfeit in the market, with flavors and properties completely contrary to expectations. Not only will they fail to treat the disease correctly, but they may also aggravate it. If users do not examine carefully and administer them casually, once swallowed, there is no return; life and death are decided instantly. Is this not terrifying? Thus, many who take medicines die, while those who do not take medicines survive.
In the Gengyin year, I was appointed to an official post in the capital. A senior relative of my clan, also awaiting appointment as a Prefect, was residing in Minzhong Temple. He had suffered from a chronic illness for two years but firmly refused medication, relying only on regulating his breathing, diet, and daily routine. His condition neither improved nor worsened. A close friend visited him in the capital, went to Minzhong Temple to visit him, and strongly recommended a physician, praising his miraculous healing skills. Unable to refuse, the senior relative reluctantly engaged the doctor. The friend purchased the herbs with great enthusiasm, predicting immediate effects. The senior relative feigned agreement. Although the decoction was prepared, he did not touch his lips to it. The next day, the friend fell ill himself, though not severely, and used the medicine prescribed by the recommended physician. The senior relative sent his servant daily to inquire after the friend's health, perhaps to acknowledge the friend's previous kindness. Just a few days later, the servant returned suddenly to report: "The close friend has died." The senior relative sighed with regret. Soon after, his own illness completely healed, and he obtained his official appointment and left the capital.
Furthermore, my clan uncle, Mr. Tao Cun, who served as the Magistrate of Laiyang County, had his eldest son suffer from Wind-Cold disease. Various physicians failed to produce any effect. Upon seeking a renowned physician, several doses of medicine were administered, but the condition worsened critically. When the physician arrived, the patient firmly refused treatment. The physician shouted loudly, "The medicinal power cannot overcome the pathogen. If taking more medicine is ineffective, I accept punishment." Half-doubting and half-believing, the uncle forced his son to swallow the medicine. Shortly thereafter, phlegm surged, and breath ceased immediately. They urgently sought another physician, but he had fled without a trace. Alas, how terrifying! Books record countless instances of quacks killing patients, which cannot be fully enumerated; these are cases I have witnessed with my own eyes and ears.
One might ask: "Should medicine then be abolished?" I reply: "How could it be? One must simply be cautious." Being cautious about medicine is less important than being cautious about disease; and being cautious about disease requires understanding it. Therefore, I will now categorically explain the causes of disease in the Five Zang Organs, errors in disease differentiation, and secrets to avoiding disease. Among hundreds of disease types, I have selected only those that are common and easily contracted. This aims to enable people to know what to guard against before illness strikes, so that they may attain longevity and health without needing to rely on hospitals or pharmacies.
According to the preface of Dongyuan's *Gezhi Yulun*: "Therefore, formulas and diseases rarely match perfectly; adhering rigidly to formulas can kill people." This compilation records diseases but does not include formulas, reflecting this very principle.