寒伤形，热伤气。气伤痛，形伤肿。故先痛而后肿者，气伤形；先肿而后痛者，形伤气也。（《素问》。）
病在阳者命曰风，在阴者命曰痹，阴阳俱病命曰风痹。病有形而不痛者，阳之类也。无形而痛者，阴之
类也。（阴痹者，按之不可得。）无形而痛者，其阳完而阴伤之也，急治其阴，无
攻其阳。有形而不痛者，其阴完而阳伤之也，急治其阳，无攻其阴。阴阳俱动，乍有形，乍无形，加以
烦心，命曰阴胜其阳，此谓不表不里，其形不久。（《灵枢》。）
形盛脉细，少气不足以息者危。形瘦脉大，胸中多气者死，形气相得者生。（平人气胜形者寿。病而形肉
脱，气胜形者死，形胜气者危。）目眶内陷者死。皮肤着（入声，枯也。）者死。脱肉，身不
去者死。形肉已脱，九候虽调，犹死。若夫急虚身中，譬如堕溺，不可为期，其形肉虽不脱，犹死也。（病而
气胜形者，喘息低昂，抬肩撼胸。）
形弱气虚死。形气有余，脉气不足死。脉气有余，形气不足生。
气盛身寒，（恶寒。）得之伤寒。气虚身热，（恶热。）得之伤暑。谷入多而气少者，得之有所脱血，湿居下也。
谷入少而气多者，邪在胃及与肺也。脉小血多者，饮中热也。脉大血少者，脉有风气，水浆不入也。（《素问》。）
形气不足，病气有余，是邪胜也，急当泻之。形气有余。病气不足，急当补之。形气不足，病气不足，此
阴阳俱不足也。不可刺之，刺之重不足，则阴阳俱竭，血气皆尽，五脏空虚，筋骨髓枯，老者灭绝，壮者
不复矣。形气有余，病气有余，此阴阳俱有余也。急泻其邪，调其虚实。李东垣曰∶
病来潮作之时，病气精神增添者，是为病气有余，乃邪气胜也，急泻之。病来潮作之时，神气困弱者，为病
气不足，乃真气不足也，急补之。不问形气有余不足，只从病气上分别补泻。形谓皮肉筋骨血脉也，气谓
口鼻气息也。（东垣释《内经》，出《内外伤辨》。）
寒气损伤形体，热气损伤气机。气机受损导致疼痛，形体受损导致肿胀。所以先出现疼痛而后出现肿胀的，是气伤及形；先出现肿胀而后出现疼痛的，是形伤及气。（出自《素问》。）
病位在阳分的称为风，在阴分的称为痹，阴阳两分都患病的称为风痹。病症有形体表现但不疼痛的，属于阳类。没有形体表现但疼痛的，属于阴类。（阴痹患者，按压时无法触及痛点。）没有形体表现但疼痛的，说明阳气完好而阴气受伤，应紧急治疗阴分，不要攻伐阳气。有形体表现但不疼痛的，说明阴气完好而阳气受伤，应紧急治疗阳气，不要攻伐阴气。阴阳都出现异常波动，时而显现形体症状，时而无形体症状，再加上心烦意乱，这叫做阴胜过阳，这种情况被称为既不在表也不在里，预后不良，生命难以长久。（出自《灵枢》。）
形体壮盛但脉象细弱，气息短少不足以呼吸的，病情危重。形体消瘦但脉象洪大，胸中气机壅滞的，主死。形体与气机相协调的，主生。（正常人气血旺盛超过形体者长寿。患病后肌肉脱失，若气机仍强盛于形体者主死，若形体尚存而气机衰败者主危。）眼眶内陷的，主死。皮肤枯槁紧贴骨节的，主死。肌肉严重脱失，身体僵硬不能转动的，主死。形体肌肉已经脱失，即使三部九候脉象调和，也主死。如果是急骤的虚邪侵袭人体，如同坠落溺水一般突然发病，病程难以预测，虽然肌肉尚未完全脱失，但也主死。（患病后气机强盛于形体，表现为喘息声高低起伏，抬肩撼动胸部。）
形体虚弱且气机不足的，主死。形体气机有余，但脉气不足的，主死。脉气有余，但形体气机不足的，主生。
气机亢盛而身体畏寒的，（恶寒。）是由于感受伤寒所致。气机虚弱而身体发热的，（恶热。）是由于感受暑邪所致。饮食摄入多但气少的，是由于失血或湿邪居于下焦所致。饮食摄入少但气多的，是邪气在胃和肺所致。脉象小但血量多的，是饮停化热所致。脉象大但血量少的，是脉中有风邪，且水浆无法入喉所致。（出自《素问》。）
形体气机不足，而病邪气机有余，这是邪气胜实，应当紧急采用泻法。形体气机有余，而病邪气机不足，应当紧急采用补法。形体气机不足，病邪气机也不足，这是阴阳俱虚。不可使用针刺治疗，如果误刺导致更虚，就会使阴阳俱竭，血气耗尽，五脏空虚，筋骨骨髓枯竭，老年人会死亡，青壮年也无法恢复。形体气机有余，病邪气机也有余，这是阴阳俱实。应当紧急泻除邪气，调理虚实。李东垣说：疾病发作之时，如果患者的精神状态反而增强，这是病气有余，乃邪气胜实，应当紧急泻之。疾病发作之时，如果神气困倦衰弱，这是病气不足，乃真气不足，应当紧急补之。不论形体气机是否有余不足，只从病气的角度来区分补泻。所谓“形”，指皮、肉、筋、骨、脉；所谓“气”，指口鼻呼吸之气。（李东垣对《内经》的解释，出自《内外伤辨惑论》。）
Cold pathogenic factors damage the *xing* (physical structure/body), while heat pathogenic factors damage *qi* (vital energy). Damage to qi leads to pain, and damage to xing leads to swelling. Therefore, if pain occurs first followed by swelling, it indicates that qi has damaged xing; if swelling occurs first followed by pain, it indicates that xing has damaged qi. (From *Suwen*.)
Diseases located in the Yang aspect are termed *Feng* (Wind), those in the Yin aspect are termed *Bi* (Obstruction/Syndrome), and those affecting both Yin and Yang are termed *Feng-Bi*. Diseases with physical manifestations but without pain belong to the category of Yang. Diseases without physical manifestations but with pain belong to the category of Yin. (In cases of Yin Bi, pressing on the area yields no tenderness.) When there is no physical manifestation but there is pain, it means Yang is intact while Yin is injured; urgently treat Yin, do not attack Yang. When there is a physical manifestation but no pain, it means Yin is intact while Yang is injured; urgently treat Yang, do not attack Yin. When both Yin and Yang fluctuate abnormally, alternating between having physical manifestations and being formless, accompanied by vexation and heart discomfort, this is termed "Yin surpassing Yang." This condition is described as neither exterior nor interior, and the prognosis is poor, with life expectancy short. (From *Lingshu*.)
If the body is robust but the pulse is thin, and there is shortness of breath insufficient for respiration, the condition is critical. If the body is emaciated but the pulse is large, and there is excessive Qi sensation in the chest, death ensues. If the body and Qi are in harmony, survival is indicated. (Normally, individuals whose Qi exceeds their physical form live long. In disease, if muscle wasting occurs and Qi still exceeds the form, death ensues; if the form remains but Qi is deficient, the condition is critical.) Sunken eye sockets indicate death. Skin that is dry and adheres tightly to the bone indicates death. Severe muscle wasting with a stiff body unable to move indicates death. If the physical flesh and muscles have already wasted away, even if the pulses at all nine positions are harmonious, death still ensues. In cases of sudden severe deficiency where the pathogen strikes the body suddenly, like falling into water or drowning, the course cannot be predicted; even if the flesh has not completely wasted away, death ensues. (When Qi exceeds the form in disease, it manifests as loud breathing with varying pitch, lifting shoulders and heaving the chest.)
If the form is weak and Qi is deficient, death ensues. If the form and Qi are abundant but the pulse Qi is deficient, death ensues. If the pulse Qi is abundant but the form and Qi are deficient, survival is indicated.
If Qi is abundant but the body feels cold (aversion to cold), it results from Cold damage. If Qi is deficient but the body feels hot (aversion to heat), it results from Summerheat damage. If food intake is high but Qi is low, it results from blood loss or Dampness residing in the lower jiao. If food intake is low but Qi seems high, the pathogen is in the Stomach and Lungs. If the pulse is small but blood volume is high, it indicates Heat within fluid retention. If the pulse is large but blood volume is low, it indicates Wind pathogen in the vessels and inability to ingest fluids. (From *Suwen*.)
If the form and Qi are deficient, but the pathogenic Qi is abundant, this indicates excess of evil; urgently apply draining methods. If the form and Qi are abundant, but the pathogenic Qi is deficient, urgently apply tonifying methods. If both the form/Qi and the pathogenic Qi are deficient, this indicates deficiency of both Yin and Yang. Acupuncture should not be used; if needled, it will cause further deficiency, leading to exhaustion of both Yin and Yang, depletion of blood and Qi, emptiness of the five Zang organs, and withering of sinews, bones, and marrow. The elderly will perish, and the strong will not recover. If both the form/Qi and the pathogenic Qi are abundant, this indicates excess of both Yin and Yang. Urgently drain the evil pathogen and regulate deficiency and excess. Li Dongyuan stated: When the disease flares up, if the patient's spirit and vitality increase, this is excess of pathogenic Qi, indicating dominance of evil pathogen; urgently drain it. When the disease flares up, if the spirit and Qi are fatigued and weak, this is deficiency of pathogenic Qi, indicating deficiency of true Qi; urgently tonify it. Regardless of whether the form and Qi are abundant or deficient, distinguish tonification and drainage solely based on the pathogenic Qi. "Form" refers to skin, flesh, sinews, bones, and vessels; "Qi" refers to the breath from mouth and nose. (Li Dongyuan's interpretation of *Neijing*, from *Bian Huo Lun*.)