针经云。陷下则灸之。天地间无他。惟阴与阳二气而已。阳在外在上。阴在内在下。今
言
陷下者。阳气下陷。入阴血之中。是阴反居其上。而复其阳。脉证俱见。寒在外者则灸之。
异法方宜论云。北方之人宜灸 也。为冬寒大王。伏阳在内。皆宜灸之。以至理论。则肾主
脏
脏阳气在内。冬三月。主闭脏是也。若太过。则病固宜灸 。此明陷入阴水之中是也。难
经云。热病在内。取阳之气穴。为阳陷入阴中。取气通天之窍穴。以火引火而导之。此宜灸
也。若将有病者。以概灸之。岂不误哉。仲景云。微数之脉。慎不可灸。因火为邪。则为
烦逆。追虚逐实。血散脉中。火气虽微。内攻有力。焦骨伤筋。血难复也。又曰。脉浮、宜
以汗解。因火灸之。邪无从出。因火而胜。病从腰以下。必重而痹。名火逆也。脉浮热甚。
而反灸之。此为实。实以虚治。因火而动。必咽燥唾血。
又云。身穴三百六十有五。其三十穴灸之有害。七十九穴。刺之为灾。并中髓也。按明
堂针
经各条下。所说禁忌明矣。内经云。脉之所见。邪之所在。脉沉者。邪气在内。脉浮者。邪
气
在表。世医只知脉之说。不知病证之禁忌。若表见寒证。身汗出。身常清。数栗而寒。不渴
欲覆浓衣裳。恶寒。手足厥。皮肤干枯。其脉必沉细而迟。但有一二证。皆宜灸之。阳气
下陷故也。若身热恶热。时见躁作。或面黄咽干。嗌干。口干。舌上黄赤。时渴咽嗌痛。皆
热在外也。但有一二证。皆不宜灸。其脉必浮数。或但数亦不可灸。灸之、灾害立生。若有
鼻不闻香臭。鼻流清涕。眼脸时痒。或欠或嚏。恶寒。其脉必沉。是脉证相应也。或轻手得
弦紧者。是阴伏其阳也。虽面赤亦宜之。不可拘于面赤色而禁之也。便有脑痛恶寒者。虽面
赤宜灸风府穴。如带遍脑痛。更恶风者。邪在少阳。宜灸风池。兼灸风府。然艾炷不宜大。
但如小麦粒。一七壮足矣。若多艾注。大防损目。
《针经》说：脉象沉陷无力的，应当用灸法。天地间没有别的，只有阴气和阳气二气罢了。阳气在外、在上；阴气在内、在下。现在所说的“陷下”，是指阳气下陷，进入阴血之中，导致阴气反而居于上面，此时需要恢复阳气。当脉象和证候都表现出寒气在外的情况时，就应当使用灸法。
《异法方宜论》说：北方的人适宜用灸法。因为那里冬天寒冷盛行，阳气伏藏于体内，所以都适宜用灸法。从医理上分析，肾主管脏气的阳气存在于体内，冬季三个月，主司闭藏脏气，如果阳气太过（或指寒邪太盛导致阳气被郁），则生病，适宜用灸法。这明确指出了阳气陷入阴水之中的情况。
《难经》说：热病在体内，要选取阳经的气穴。这是因为阳气陷入阴中，需要选取与天相通窍的穴位，以火引火来引导它。这种情况适宜用灸法。如果将有病的人都一概用灸法，难道不是错误吗？
张仲景说：脉象微细而数的，千万不可灸。因为火邪会成为致病因素，导致烦闷逆乱，耗伤正气、追逐实邪，使血液散乱于脉中。火气虽然微弱，但内攻的力量很强，会焦骨伤筋，血液难以恢复。又说：脉浮，适宜用发汗的方法解表。如果因用火灸治，邪气就没有出路，反而因火邪而亢盛，疾病发展到腰部以下，必定沉重且麻木不仁，这叫作“火逆”。脉浮且热势很盛，却反而用灸法，这是实证，却用虚证的方法治疗，因火邪扰动，必定导致咽喉干燥、唾血。
又说道：全身穴位共有三百六十五个，其中三十个穴位灸治会有害处，七十九个穴位针刺会造成灾祸，这些都是因为刺中了髓。查看《明堂针经》各条目下的记载，所说的禁忌非常明确。
《内经》说：脉象所显现的地方，就是邪气所在之处。脉沉，说明邪气在体内；脉浮，说明邪气在体表。世间的医生只知道脉象的说法，却不知道病证的禁忌。如果体表出现寒证，身体出汗，身体经常感觉清冷，频繁战栗发冷，口不渴想要覆盖厚衣服，怕冷，手脚冰凉，皮肤干枯，其脉象一定是沉细而迟缓的。只要具备其中一两个证候，都适宜用灸法，这是因为阳气下陷的缘故。
如果身体发热、怕热，时常烦躁发作，或者面色黄、咽喉干、喉咙干、口干、舌苔黄赤，时常口渴、咽喉疼痛，这都是热邪在体表的表现。只要具备其中一两个证候，都不适宜用灸法。其脉象一定是浮数，或者只是数脉也不可以灸。如果灸了，灾害立刻产生。如果有鼻子闻不到香味和臭味，流清鼻涕，眼睑时常发痒，或者打哈欠、打喷嚏，怕冷，其脉象一定是沉的，这是脉证相应。或者轻取就能得到弦紧的脉象，这是阴伏住了阳气。即使面色发红也适宜用灸法，不可以拘泥于面色红这一现象而禁止灸法。如果有头痛、怕冷的情况，即使面色发红，也适宜灸风府穴。如果头痛遍及头部，更加怕风，说明邪气在少阳经，适宜灸风池穴，兼灸风府穴。但是艾炷不宜过大，只要像小麦粒那么大，灸七壮就够了。如果艾灸过多，非常担心损伤眼睛。
The *Zhen Jing* (Classic of Acupuncture) states: "When the pulse is sunken and deflated, moxibustion should be applied." There is nothing else in heaven and earth except the two qi of Yin and Yang. Yang qi is external and superior; Yin qi is internal and inferior. The term "sunken and deflated" mentioned here refers to Yang qi sinking into the Yin blood, causing Yin to occupy the upper position instead. In such cases, one must restore the Yang. When both the pulse and symptoms indicate coldness at the exterior, moxibustion should be used.
The *Yi Fa Fang Yi Lun* (Treatise on Different Methods and Appropriate Prescriptions) states that people in the North are suitable for moxibustion. This is because winter cold is predominant there, with Yang qi hidden within the interior; thus, moxibustion is generally appropriate. From a theoretical perspective, the Kidney governs the Yang qi of the Zang organs, which resides internally. During the three months of winter, it governs the closure of the Zang organs. If this condition becomes excessive or if pathogenic factors obstruct, illness arises, and moxibustion is indicated. This clearly describes the situation where Yang qi sinks into Yin water.
The *Nan Jing* (Classic of Difficult Issues) states: "For heat diseases located internally, select Qi points of the Yang meridians." This is because when Yang qi sinks into Yin, one should select acupoints connected to Heaven to guide the pathogen using fire to lead fire. This scenario is suitable for moxibustion. However, applying moxibustion indiscriminately to all patients would certainly be erroneous.
Zhang Zhongjing stated: "If the pulse is fine and rapid, moxibustion must be avoided." Because fire can become a pathogenic factor, leading to irritability and rebellion, depleting deficiency and chasing excess, causing blood to scatter within the vessels. Although the fire qi is slight, its internal attacking power is strong; it can scorch bones and damage sinews, making blood difficult to restore. He further said: "A floating pulse indicates that sweating should be used to resolve the exterior. If moxibustion is applied due to fire, the pathogen has no outlet. Instead, it intensifies due to the fire. Below the waist, the body will become heavy and numb, a condition known as 'Fire Reversal' (Huo Ni). If the pulse is floating and heat is severe, but moxibustion is applied in reverse, this treats an Excess pattern as Deficiency. Due to the disturbance by fire, dry throat and hemoptysis (spitting blood) will inevitably occur."
It is also stated that there are 365 acupoints on the body. Moxibustion on thirty of them is harmful, and needling seventy-nine of them causes disaster, primarily because they penetrate the marrow. According to the *Ming Tang Zhen Jing* (Illustrated Manual of Acupuncture Points), the contraindications listed under each entry are clear.
The *Nei Jing* (Inner Canon) states: "Where the pulse manifests is where the pathogen resides." A deep pulse indicates the pathogen is internal; a floating pulse indicates the pathogen is external. Physicians of the world often only understand pulse diagnosis but ignore the contraindications of specific syndromes. If exterior Cold patterns manifest—such as sweating, feeling constantly cold, frequent shivering and chills, lack of thirst, desire to cover with thick clothing, aversion to cold, cold extremities, and dry skin—the pulse will necessarily be deep, fine, and slow. If even one or two of these symptoms are present, moxibustion is appropriate, as this results from sinking Yang qi.
Conversely, if the patient has fever, aversion to heat, occasional restlessness, yellow complexion, dry throat/pharynx, dry mouth, yellow-red tongue coating, frequent thirst, and sore throat, these indicate Heat at the exterior. If even one or two of these symptoms are present, moxibustion is inappropriate. The pulse will necessarily be floating and rapid, or merely rapid; in either case, moxibustion should not be used. Applying moxibustion in such cases will immediately cause disaster.
If a patient suffers from anosmia (loss of smell), runny nose with clear discharge, itchy eyelids, yawning, sneezing, and aversion to cold, the pulse will be deep, indicating correspondence between pulse and syndrome. If a wiry and tight pulse is obtained with light pressure, it indicates Yin hiding Yang. Even if the face is red, moxibustion is still appropriate; one should not strictly forbid it based solely on facial redness. For example, if there is headache and aversion to cold despite facial redness, Fengfu (GV16) is suitable for moxibustion. If the headache extends throughout the head and wind aversion is more severe, the pathogen is in the Shaoyang meridian; Fengchi (GB20) should be moxaed, along with Fengfu (GV16). However, the moxa cone should not be large; it should be the size of a wheat grain, and seven moxa cones (zhuang) are sufficient. Excessive moxibustion poses a significant risk of damaging the eyes.