灵枢经·贼风 Thief Wind
黄帝曰：夫子言贼风邪气之伤人也，令人病焉，今有其不离屏蔽，不出室穴之中，卒然病者，非不离贼风邪气，其故何也？歧伯曰：此皆尝有所伤于湿气，藏于血脉之中，分肉之间，久留而不去。若有所堕坠，恶血在内而不去，卒然喜怒不节，饮食不适，寒温不时，腠理闭而不通。其开而遇风寒，则血气凝结，与故邪相袭，则为寒痹。其有热则汗出，汗出则受风，虽不遇贼风邪气，必有因加而发焉。
黄帝曰：今夫子之所言者，皆病人之所自知也。其毋所遇邪气，又毋怵惕之所志，卒然而病者，其故何也？唯有因鬼神之事乎？歧伯曰：此亦有故邪留而未发，因而志有所恶，及有所慕，血气内乱，两气相搏。其所从来者微，视之不见，听而不闻，故似鬼神。
黄帝曰：其祝而已者，其故何也？歧伯曰：先巫者，因知百病之胜，先知其病之所从生者，可祝而已也。
Huangdi said: "You have said that thief winds and evil qi injure people and cause illness. But now there are those who never leave their shelter, who never go out from within their chambers, and yet suddenly fall ill — this is not because they have failed to avoid thief winds and evil qi. What is the reason for this?" Qibo said: "These are all cases in which the person had previously been injured by damp qi, which became hidden within the blood vessels and between the muscle divisions, lingering there for a long time without leaving. Or perhaps there had been a fall or injury, so that malign blood remained within and was not dispelled. Then, suddenly, joy or anger became unregulated, eating and drinking became improper, or cold and warmth were not seasonable, causing the interstitial texture to close and become impassable. If the interstices then open and one encounters wind and cold, the qi and blood congeal and bind together, and this joins with the old lingering evil to become cold impediment. If instead there is heat, sweating occurs, and sweating exposes one to wind — thus even without directly encountering thief wind and evil qi, illness will inevitably erupt because of these compounding causes."
Huangdi said: "What you have described are all cases the patient can recall for himself. But what of one who has encountered no evil qi and has had no fright or apprehension in his mind, yet suddenly falls ill — what is the reason for this? Is it perhaps due to the doings of ghosts and spirits?" Qibo said: "This too is a case where an old evil has lingered without yet erupting. Then, because the mind comes to harbor aversion toward something, or attachment and longing for something, the qi and blood become disordered within, and the two qi contend with one another. Since the origin of this is subtle, it cannot be seen by looking nor heard by listening, and so it seems to resemble the doings of ghosts and spirits."
Huangdi said: "What is the reason that such illness can be cured by incantation alone?" Qibo said: "The shamans of old, because they understood what could overcome the hundred diseases, and knew in advance the origin from which each illness arose, were able to cure it by incantation alone."