世有一等孩童，生得体质魁肥，似血气有余也，何患痘疮，则囊房空虚，不至
灌浆成脓，八九日而死者，何欤？盖天元不可以形拘，气血宁堪以质定，彼形体虽
瘦小，而元气充溢，则痘自然起灌成功。如形体魁大而元气薄劣，则痘必至枯涩难长，
故治痘看人元气，不可拟以形体。况痘有经络部位之不同，多寡大小之不一，气运
时令之不齐，调摄爱养之得失，岂可以形体论哉！故痘之经络既正，颗粒稀朗，气
运淑顺，调摄合宜，枭毒原浅，则瘦小而元气实者，固不为害，即瘦小而原气弱者，
亦有生矣。如痘之经络错犯，点数密，且时令乖逆，调理戾常，枭毒禀盛，则肥胖
而气血衰者，固罹其厄，即肥胖而气血盛者，亦有死者矣。况瘠黑者骨坚肉硬，且
气固于中，骨胜肉也，出痘多吉，肥白者骨脆肉松，且气居于表，肉胜骨也，出痘多凶，盖肾主骨，痘为肾毒耳。
夫不知虚实者，不可以为工。经曰∶毋实实，毋虚虚。故虚实之分，不可不知也。
经曰∶必先度其形之肥瘦，以调其气之虚实。此以形体别虚实也。又曰∶谷盛气盛，
谷虚气虚。此以饮食别虚实也。又曰∶脉实血实，脉虚血虚。此以脉别虚实也。又
曰∶邪气盛则实，精气夺则虚。此以邪正别虚实也。大抵实者邪气实，虚者正气虚。
经曰∶邪之所凑，其气必虚。留而不去，其病则实是也。又云∶五实死者，谓邪气之
实也。五虚死者。谓正气之虚也。凡痘疮之证，其人形体肥健，饮食能多，六脉洪
实，素无疾病，大便如常，疮色红润者，此表里正气俱实也，不须服药；若形体羸瘦，
素多疾病，饮食减少，六脉微弱，吐利频频，疮色淡嫩者，此表里正气俱虚也，治
宜温补之法。如疮势太盛， 肿痛胀，大热不退，烦渴昏睡，大小便秘者，此表里
邪气俱实也，治宜凉泻之法。如疮本稠密， 发红活而吐利不食者，此表实里虚也，宜
于补汤中而加解毒之药。如疮色淡白，发不透满，大小便秘，浩饮大嚼者，此里实
表虚也，宜于解利中而加升发之药。如诸痛为实，然疮痛者邪气实也，当活血以开
其郁，至若痛如刀割，闷乱大叫者勿治。诸痒为虚，然疮痒者正气虚也，当补气以燥
其湿，至若爬搔不定，破烂皮脱者，勿治。灰白者，气虚也，参 之功为大；干燥者
血虚也，归芎之功宜多；虚则补之，实则泻之，中病则已，无过其制，此治之权衡
也。若本实而反补之，是皆补之过也。如本虚而反泻之，则正气益虚，或为吐利，或
为厥逆，是皆泻之过也。经曰∶毋致邪，毋失正，绝人长命，此之谓欤！
世间有一类孩童，生得体格魁梧肥胖，看似血气有余，为何患痘疮时，痘囊空虚，不能灌浆化脓，在第八九日便死亡呢？这是因为先天元气不能被形体所拘束，气血岂能仅凭体质形态来判定？那些形体虽然瘦小，但元气充溢的，痘疮自然能够起发、灌浆而痊愈。如果形体魁梧庞大但元气薄弱低劣，痘疮必然干枯涩滞难以生长。因此治疗痘疮要看人的元气，不可用形体来推测。况且痘疮有经络部位的不同，多少大小的不一，运气时令的差异，调摄养护的得失，怎么可以单凭形体来判断呢！所以痘疮的经络既正，颗粒稀疏明朗，运气和顺，调摄适宜，毒邪原本浅薄，那么瘦小且元气充实的人，固然不会有害；即使是瘦小且元气虚弱的人，也有生存的希望。如果痘疮的经络错乱触犯，点数密集，且时令乖逆，调理违背常理，毒邪禀赋强盛，那么肥胖且气血衰弱的人，固然会遭受厄运；即使是肥胖且气血旺盛的人，也有死亡的案例。况且瘦黑的人骨骼坚固肌肉坚硬，且气固守于内，骨胜于肉，出痘多吉利；肥胖白嫩的人骨骼脆弱肌肉松弛，且气浮居于表，肉胜于骨，出痘多凶险，因为肾主骨，痘疮是肾毒所致。
不知道虚实辨证的，不可以成为医生。经书说：不要使实证更实，不要使虚证更虚。所以虚实的区分，不可不明了。经书说：必须先衡量其形体的肥瘦，来调节其气的虚实。这是通过形体来辨别虚实。又说：饮食旺盛则气盛，饮食匮乏则气虚。这是通过饮食来辨别虚实。又说：脉象实则血实，脉象虚则血虚。这是通过脉象来辨别虚实。又说：邪气盛则表现为实证，精气被耗夺则表现为虚证。这是通过邪正关系来辨别虚实。大体上，实证是邪气实，虚证是正气虚。经书说：邪气聚集的地方，正气必定虚弱。邪气停留不去，疾病就表现为实证了。又说：出现五种实证症状而死的，是因为邪气实。出现五种虚证症状而死的，是因为正气虚。凡是痘疮的病证，如果其人形体肥壮健康，饮食能多，六脉洪大有力，平素无疾病，大便正常，疮色红润的，这是表里正气都充实，不需要服药；如果形体消瘦，平素多病，饮食减少，六脉微弱，频繁呕吐腹泻，疮色淡嫩的，这是表里正气都虚弱，治疗宜用温补的方法。如果疮势太盛，肿痛胀大，高热不退，烦躁口渴昏睡，大小便闭塞的，这是表里邪气都实，治疗宜用凉泻的方法。如果疮本来稠密，发红活却伴有呕吐腹泻不能进食的，这是表实里虚，应在补益汤剂中加入解毒的药物。如果疮色淡白，发不透满，大小便闭塞，大量饮水大口吃东西的，这是里实表虚，应在解表通利药中加入升发透疹的药物。凡是疼痛属于实证，然而疮痛是邪气实，应当活血以开通郁结，至于像刀割一样疼痛，烦闷扰乱大声呼叫的，不要治疗。凡是瘙痒属于虚证，然而疮痒是正气虚，应当补气以燥湿，至于抓挠不定，皮肤破烂脱落的，不要治疗。颜色灰白的，是气虚，人参的功效最大；干燥的，是血虚，当归、川芎的功效适宜多用。虚则补之，实则泻之，中病即止，不超过法度，这是治疗的权衡准则。如果本是实证反而补它，这是补之过当。如果本是虚证反而泻它，则正气更加虚弱，或者导致呕吐腹泻，或者导致四肢厥冷逆乱，这都是泻之过当。经书说：不要助长邪气，不要损伤正气，断送人的寿命，说的就是这个道理啊！
There are children in the world who are born with a robust and obese physique, seemingly indicating an abundance of blood and qi. Why do they suffer from smallpox, where the pustules remain empty, fail to fill with pus, and result in death on the eighth or ninth day? This is because the innate Yuan Qi (vital energy) cannot be constrained by physical form, nor can blood and qi be determined solely by constitution. Those who are physically thin but have abundant Yuan Qi will naturally see their smallpox erupt, fill, and heal successfully. Conversely, those who are physically large but have weak and inferior Yuan Qi will find their smallpox dry, astringent, and difficult to grow. Therefore, treating smallpox requires assessing the patient's Yuan Qi; one must not speculate based on physical appearance. Moreover, smallpox varies in meridian pathways and locations, number and size, seasonal influences, and the efficacy of care and nurturing. How can it be judged merely by physique! Thus, if the smallpox follows correct meridians, presents with sparse and clear lesions, aligns with favorable seasonal rhythms, and receives appropriate care, even if the toxin is originally shallow, a thin person with solid Yuan Qi will certainly not be harmed. Even a thin person with weak Yuan Qi may survive. However, if the smallpox invades incorrect meridians, presents with dense spots, occurs during adverse seasons, involves improper management, and carries a strong toxic constitution, then an obese person with deficient blood and qi will surely suffer misfortune. Even an obese person with abundant blood and qi may die. Furthermore, lean and dark-skinned individuals have firm bones and hard muscles, with qi secured internally and bone surpassing muscle; they tend to have auspicious outcomes with smallpox. Fat and fair-skinned individuals have fragile bones and loose muscles, with qi floating externally and muscle surpassing bone; they tend to have ominous outcomes with smallpox. This is because the Kidneys govern bones, and smallpox is considered a toxin of the Kidneys.
One who does not understand deficiency and excess cannot be a competent physician. The Classics state: Do not reinforce excess, and do not deplete deficiency. Therefore, the distinction between deficiency and excess must be clearly understood. The Classics state: First, measure the fatness or leanness of the body to regulate the deficiency or excess of qi. This distinguishes deficiency and excess through physical form. It also states: Abundant food intake leads to abundant qi; deficient food intake leads to deficient qi. This distinguishes deficiency and excess through diet. It further states: A surging pulse indicates abundant blood; a weak pulse indicates deficient blood. This distinguishes deficiency and excess through pulse diagnosis. It also states: When pathogenic factors are abundant, it manifests as excess; when essential qi is depleted, it manifests as deficiency. This distinguishes deficiency and excess through the relationship between pathogens and healthy qi. Generally, excess refers to the abundance of pathogenic factors, while deficiency refers to the insufficiency of healthy qi. The Classics state: Wherever pathogenic factors gather, healthy qi must be deficient. If they remain and do not depart, the disease manifests as excess. It is also said: Death from the five excess conditions results from the abundance of pathogenic factors. Death from the five deficiency conditions results from the insufficiency of healthy qi. In cases of smallpox, if the patient has a robust and healthy physique, good appetite, surging and forceful pulses across all six positions, no prior illnesses, normal bowel movements, and red, lustrous lesions, this indicates that both exterior and interior healthy qi are solid; medication is unnecessary. If the patient is emaciated, frequently ill, has reduced appetite, weak and faint pulses across all six positions, frequent vomiting and diarrhea, and pale, tender lesions, this indicates that both exterior and interior healthy qi are deficient; treatment should employ warming and tonifying methods. If the lesion progression is too vigorous, with severe swelling, pain, distension, persistent high fever, restlessness, thirst, drowsiness, and constipation of urine and stool, this indicates that both exterior and interior pathogenic factors are excessive; treatment should employ cooling and purgative methods. If the lesions are originally dense, red, and vibrant, yet accompanied by vomiting, diarrhea, and inability to eat, this indicates exterior excess and interior deficiency; detoxifying herbs should be added to tonic decoctions. If the lesions are pale white, fail to fully erupt, accompanied by constipation of urine and stool, yet the patient drinks heavily and eats voraciously, this indicates interior excess and exterior deficiency; ascending and diffusing herbs should be added to exterior-resolving and promoting formulas. Generally, pain indicates excess; however, pain from sores is due to excess pathogenic factors, requiring blood-invigorating methods to resolve stagnation. But if the pain is like knife-cutting, accompanied by mental confusion and loud crying, do not treat. Generally, itching indicates deficiency; however, itching from sores is due to deficient healthy qi, requiring qi-tonifying methods to dry dampness. But if scratching is incessant, with skin breakdown and peeling, do not treat. Grayish-white color indicates qi deficiency; Ren Shen (Ginseng Radix et Rhizoma) is most effective. Dryness indicates blood deficiency; Dang Gui (Angelicae Sinensis Radix) and Chuan Xiong (Ligusticum Chuanxiong Rhizoma) are most suitable. Deficiency is treated by tonification, excess by purgation; cease treatment once the illness is addressed, without exceeding the prescribed limits; this is the balance of treatment. If one tonifies when there is actual excess, it is an error of over-tonification. If one purges when there is actual deficiency, healthy qi becomes further depleted, potentially leading to vomiting, diarrhea, or cold extremities and reversal; these are errors of over-purgation. The Classics state: Do not aid the pathogen, do not lose the healthy qi, thereby cutting short human life—this is what is meant!