治病有八要。八要不审，病不能去。非病不去，医无可去之术也。故须辨审八要，庶不有误。
其一曰虚，五虚是也。脉细，皮寒，气少，前后泻泄，饮食不进，此为五虚。二曰实，五实
是也。脉盛，皮热，腹胀，前后不通，闷瞀，此五实也。三曰冷，脏腑受其积冷是也。四曰热，
脏腑受其积热是也。五曰邪，非脏腑正病也。六曰正，非外邪所中也。七曰内，病不在外也。八
曰外，病不在内也。既先审此八要，参之六脉，审度所起之源，继以望闻问切，何有不可治之疾
也？（《本草衍义》）
疗病先察其源，候其病机。五脏未虚，六腑未竭，血气未耗，精神未散，服药必活。若病已
成，可得半已；病势已过，今将难全。
《淮南子》曰∶神农尝百草之滋味，当此之时，一日而遇七十毒。《世本》曰∶神农和药济
人。则百药自神农始也。《世纪》或云∶伏羲尝味百草，非也。梁陶弘景《本草》序曰∶神农氏
治天下，宣药疗疾，以拯夭
伤。高氏小史曰∶炎帝尝百药以治病，尝药之时，百死百生。《帝王世纪》曰∶炎帝尝味草木，
宣药疗疾者，《本草》四卷。至梁陶弘景、唐李世绩等注共二十卷。皇朝开宝中重校定，仁宗嘉
中命禹锡等集类诸家杂药之说，为《补注本草》。《唐书》于志宁传中，志宁云∶班固唯记
《黄帝内外经》，不载《本草》，剂《七录》乃称之，世谓神农尝药。黄帝以前，文本不传，以
识相付，至桐雷乃载篇册。然所载郡县多汉时张仲景华佗窜语。其语梁陶弘景此书，应与《素问》
同类，其余与志宁之说同也。（《事物纪原》）
治病有八个关键要点。如果不仔细审察这八个要点，疾病就无法去除。并非疾病本身不可去除，而是医生没有能够去除疾病的方法。因此必须辨别并审察这八个要点，才不至于出现误诊误治。
其一称为“虚”，即五虚证。脉象细弱，皮肤寒冷，气短少力，大小便泄泻，饮食无法进服，这叫做五虚。其二称为“实”，即五实证。脉象盛大，皮肤发热，腹部胀满，大小便不通畅，胸闷昏乱，这叫做五实。其三称为“冷”，是脏腑受到积寒所致。其四称为“热”，是脏腑受到积热所致。其五称为“邪”，指非脏腑本身的正病（指外邪侵袭）。其六称为“正”，指非外邪所中（指正气不足或内伤）。其七称为“内”，指病位不在体表而在体内。其八称为“外”，指病位不在体内而在体表。既然先审察了这八个要点，再结合六脉诊法，审度疾病的起源，继之以望、闻、问、切四诊合参，还有什么疾病是不可治愈的呢？（引自《本草衍义》）
治疗疾病首先要考察病因源头，候察病机变化。如果五脏尚未虚弱，六腑尚未衰竭，血气尚未耗损，精神尚未涣散，服药后必定能痊愈。如果疾病已经形成，只能治好一半；如果病势已经过去（指正气大衰或病程晚期），现在想要完全康复就难了。
《淮南子》说：神农品尝百草的味道，在这个时候，一天之内遭遇七十种毒性。《世本》说：神农调和药物以救济世人。那么百药确实是从神农开始的。《世纪》有人说是伏羲品尝百草味道，这是不对的。梁代陶弘景在《本草》序中说：神农氏治理天下，宣扬药物以治疗疾病，用来拯救夭折和受伤的人。高氏《小史》说：炎帝尝试百药来治疗疾病，尝试药物时，经历多次死亡又多次复活。《帝王世纪》说：炎帝品尝草木味道，宣扬药物以治疗疾病的著作，是《本草》四卷。到了梁代陶弘景、唐代李世绩等人注释，共有二十卷。本朝开宝年间重新校订，仁宗嘉祐年间命令禹锡等人汇集各家关于杂药的论述，编成《补注本草》。《唐书》于志宁传中，于志宁说：班固只记载了《黄帝内外经》，没有记载《本草》，直到《七录》才提到它，世人称之为神农尝药。黄帝以前的文本本来没有流传下来，是通过口耳相传，直到桐君、雷公才将其记载在篇册中。然而其中所载的郡县名称多带有汉代张仲景、华佗时代的语言痕迹。对此，梁代陶弘景认为此书应与《素问》同类，其余观点与于志宁的说法相同。（引自《事物纪原》）
There are eight essential principles in treating diseases. If these eight principles are not carefully examined, the disease cannot be eliminated. It is not that the disease itself is incurable, but rather that the physician lacks the methods to cure it. Therefore, one must distinguish and examine these eight essentials to avoid errors.
The first is called "Deficiency" (Xu), specifically the Five Deficiencies. A fine pulse, cold skin, shortness of breath, diarrhea of both bowels, and inability to eat constitute the Five Deficiencies. The second is called "Excess" (Shi), specifically the Five Excesses. A surging pulse, hot skin, abdominal distension, obstruction of both bowels, chest stuffiness, and dizziness/confusion constitute the Five Excesses. The third is called "Cold," referring to accumulated cold affecting the Zang-Fu organs. The fourth is called "Heat," referring to accumulated heat affecting the Zang-Fu organs. The fifth is called "Evil" (Xie), indicating pathogenic factors external to the proper state of the Zang-Fu organs. The sixth is called "Righteous/Normal" (Zheng), indicating conditions not caused by external pathogens. The seventh is called "Interior" (Nei), indicating the disease is located inside the body. The eighth is called "Exterior" (Wai), indicating the disease is located on the exterior of the body. Having first examined these eight essentials, combined with the examination of six pulses, analyzed the origin of the disease, and followed by the four diagnostic methods of Inspection, Auscultation-Olfaction, Inquiry, and Palpation, what disease would be incurable? (From *Bencao Yan Yi*)
To treat a disease, one must first investigate its source and observe its pathogenesis. If the Five Zang organs are not yet deficient, the Six Fu organs are not yet exhausted, Qi and Blood are not yet depleted, and Spirit has not yet scattered, medication will surely lead to recovery. If the disease has already formed, half may be cured; if the disease momentum has passed (indicating late stage or severe depletion), full recovery will now be difficult.
*Huainanzi* states: Shennong tasted the flavors of hundreds of herbs. At that time, he encountered seventy types of toxins in a single day. *Shiben* states: Shennong harmonized medicines to save people. Thus, the hundred medicines indeed began with Shennong. Some accounts in *Shiji* claim Fuxi tasted the herbs, which is incorrect. Tao Hongjing of the Liang Dynasty wrote in the preface to his *Bencao*: Shennong governed the world, promoted the use of medicines to treat illnesses, and saved those suffering from premature death or injury. Gao's *Xiaoshi* states: Yandi (Flame Emperor) tasted hundreds of medicines to treat diseases, experiencing death and resurrection many times during this process. *Diwang Shiji* states: Yandi tasted the flavors of plants and trees, promoting medicines to treat illnesses, resulting in four volumes of *Bencao*. By the Liang Dynasty, Tao Hongjing and the Tang Dynasty's Li Shiji provided annotations, expanding it to twenty volumes. During the Kaibao era of our dynasty, it was re-collated. In the Jiayou era of Emperor Renzong, Yu Xi and others were ordered to compile various theories on miscellaneous drugs into *Zhuben Zhu Bencao*. In the biography of Yu Zhining in the *Book of Tang*, Yu Zhining stated: Ban Gu only recorded the *Huangdi Neijing* (Yellow Emperor's Inner Canon) and did not record the *Bencao*; it was only mentioned in the *Qilu*. People call it Shennong tasting herbs. Texts prior to the Yellow Emperor were not transmitted in written form but passed down orally until Tongjun and Leigong recorded them in chapters. However, the commanderies and counties mentioned often contain language characteristic of the Han Dynasty figures Zhang Zhongjing and Hua Tuo. Regarding this, Tao Hongjing of the Liang Dynasty believed this book should be classified similarly to the *Suwen* (Basic Questions), while other aspects align with Zhining's view. (From *Shiwu Jiyuan*)