脉经曰小儿足其日数应变蒸之时身热而脉乱汗不出不欲食辄吐 者脉乱无苦也
全婴方云初生小儿变蒸者以长血气也变者上气蒸者体热巢氏病源曰自生之后每三十二日
为一
变再变为一蒸变毕即性情有异于前何者长生脏腑智意也人有三百六十五骨除手足中四十五碎
骨外有三百二十数自生下骨一日十段而上之十日百段三十二日计三百二十段为一周遍凡小儿
之病无有不因变蒸而得也而不热不惊或无他病候是暗变者多矣此受胎气壮实故也陈氏曰俗谓
之牙生骨长譬如蚕之有眠龙之脱骨虎之转爪皆此同类变生而长也其变蒸足乃生三十二齿而齿
牙而不及三十二数由变不足其常也故变蒸蜕齿者如花之易苗年壮而视齿方明总五百七十六
日大小变蒸足矣始乃成人血脉骨肉皆坚牢也每变轻则发热微汗其状似惊重则壮热脉乱而数或
吐或汗或烦啼躁渴轻者五日解重者八日解其候与伤寒相若亦有变蒸之余续感寒邪但变蒸蒸则
耳冷上唇发泡状如浊珠若寒邪传之则寒邪反攻腹中作痛而啼叫之声日夜不绝凡蒸于肝则目昏
微赤蒸于肺则嚏嗽毛耸五脏六腑筋脉骨节循环一匝各有证候其阴阳水火之变欤治法宜和平之
剂古方以黑散子紫霜丸主之
按钱氏云一变肾二变膀胱三变心四变小肠五变肝六变胆七变肺八变大肠九变脾十变胃故
称水
数一先肾也宝鉴云初变肝二变肺三变心四变脾五变肾二者所论皆五行颠逐行倒相制生者却逢相克相
克者又逢相生大抵阴阳造化相生者顺相克者逆变蒸者是长养血气滋荣五脏相生之法此理昭然
相生者有母子之道相克者有夫妇之义相生所以相继相克所以相治原夫胎者得水火既济阴阳造
化五行相治而成形故始于肾气之初生也小儿变蒸者当血气攻革阴阳升降从五脏相继而成人故
始于肝之初变也虽二家互说差殊各有所长宜详审之
《脉经》说：小儿到了特定的日数，应当进入变蒸的时期，此时身体发热而脉搏紊乱，不出汗，不想吃东西，经常呕吐，这是脉象紊乱，并无大碍。
《全婴方》说：初生小儿进行变蒸，是为了生长血气。所谓“变”，是指上部的精气变化；所谓“蒸”，是指身体的热气。巢元方的《诸病源候论》说：自出生之后，每三十二天为一个“变”，两个“变”合为一个“蒸”。变蒸结束后，孩子的性情就会与之前有所不同。为什么呢？因为这是在生长脏腑和智力意念。人有三十六块骨头（注：此处原文为三百六十五骨，系古人对人体骨骼总数的概称或传抄差异，按原文翻译），除去手足中四十五块碎骨外，还有三百二十块主要骨骼。从生下开始，骨骼每天生长十段，向上推算，十天就是一百段，三十二天共计三百二十段，这就完成了一个周期。凡是小儿的疾病，没有不是因变蒸而产生的。如果不发热、不惊厥，或者没有其他病症表现，这就是所谓的“暗变”，这种情况很多，是因为受胎时禀赋之气壮实所致。陈氏说：俗称为长牙长骨，就像蚕有眠期、龙蜕皮、虎换爪一样，都是这种同类现象，即通过变生而成长。变蒸足数后会长出三十二颗牙齿，如果牙齿数量达不到三十二颗，是由于变蒸不足其常态。所以变蒸如同花朵更换幼苗，年岁增长，看牙齿才能明确。总共经过五百七十六天的变蒸，大小变蒸都完成了，才开始成为成人，血脉骨肉都变得坚固牢靠。每次变蒸，轻的则微微发热、微汗，症状类似惊风；重的则高热、脉搏紊乱且快，或者呕吐、出汗、烦躁啼哭、口渴。轻的五天缓解，重的八天缓解。其证候与伤寒相似。也有在变蒸余势未尽时，又感受寒邪的情况，但如果是变蒸之热，则耳朵发冷，上唇起水泡，状如浑浊的珠子；如果是寒邪传入体内，则寒邪反过来攻击腹中，引起腹痛而啼叫，声音日夜不停。凡是在肝脏变蒸，则眼睛昏花微红；在肺脏变蒸，则打喷嚏咳嗽、毛发竖起。五脏六腑、筋脉骨节循环一周，各有证候，这大概是阴阳水火的变化吧。治疗方法适宜用平和的药剂，古方用黑散子、紫霜丸为主治。
按钱乙（钱氏）的说法：一变对应肾，二变对应膀胱，三变对应心，四变对应小肠，五变对应肝，六变对应胆，七变对应肺，八变对应大肠，九变对应脾，十变对应胃。所以称为水数为一，先由肾开始。《幼科发挥》（宝鉴）说：初变是肝，二变是肺，三变是心，四变是脾，五变是肾。这两家的论述，都是按照五行颠倒、逆行、相制、相生来推演的，却逢到相克；相克的又逢到相生。大体而言，阴阳造化中，相生是顺行，相克是逆变。变蒸是生长养血气、滋荣五脏相生的方法，这个道理是很明显的。相生有母子的关系，相克有夫妇的意义。相生所以相继，相克所以相互制约。原本胎儿的形成，是得到水火既济、阴阳造化、五行相治而成形，所以始于肾气的初生。小儿变蒸，当血气攻革、阴阳升降、从五脏相继而成人时，所以始于肝的初变。虽然两家的说法互相差异，但各有所长，应该详细审察。
The *Mai Jing* (Pulse Classic) states: When infants reach specific days, they enter the period of Bianzheng (periodic growth and transformation). During this time, the body may have a fever with chaotic pulse rhythms, no sweating, loss of appetite, and frequent spitting up. A chaotic pulse in this context is not harmful.
The *Quan Ying Fang* (Formulas for Infants) states: The Bianzheng process in newborns serves to grow blood and qi. "Bian" refers to the transformation of upper energies, while "Zheng" refers to bodily heat. Chao Yuanfang's *Zhu Bing Yuan Hou Lun* (Source Book of All Diseases) states: After birth, every thirty-two days constitute one "Bian." Two "Bians" combine to form one "Zheng." Upon completion of Bianzheng, the child's temperament differs from before. Why? Because this process fosters the growth of Zang-Fu organs, intelligence, and cognition. Humans are said to have 365 bones; excluding the 45 small bones in the hands and feet, there are 320 main bones. From birth, bones grow ten segments daily. Over ten days, this amounts to 100 segments; over thirty-two days, it totals 320 segments, completing one cycle. Most illnesses in children arise from the processes of Bianzheng. If there is no fever or convulsion, or other symptoms, it is called "Anbian" (hidden transformation), which is common due to strong prenatal Qi. Chen Shi states: This is colloquially known as growing teeth and bones, similar to silkworms molting, dragons shedding skin, or tigers changing claws—all are examples of growth through transformation. Upon completing the full count of Bianzheng, thirty-two teeth should emerge. Fewer teeth indicate insufficient Bianzheng. Thus, Bianzheng is like flowers replacing seedlings; only when age increases can teeth clarify the stage. After a total of 576 days of major and minor Bianzheng, the child becomes an adult, with solidified blood vessels, flesh, and bones. Mild cases involve slight fever and sweat, resembling wind-strike; severe cases involve high fever, rapid and chaotic pulses, vomiting, sweating, irritability, crying, and thirst. Mild cases resolve in five days; severe cases in eight. These symptoms resemble Taiyang disease (Exterior Syndrome). Sometimes, residual heat from Bianzheng allows cold pathogenic factors to invade. However, if it is pure Zheng heat, the ears become cold, and blisters appear on the upper lip like turbid pearls. If cold pathogens penetrate, they attack the abdomen causing pain and ceaseless day-and-night crying. Liver Zheng manifests as blurry or slightly red eyes; Lung Zheng manifests as sneezing, coughing, and erect hair. The circulation through the Five Zang and Six Fu organs, tendons, vessels, bones, and joints presents specific signs, reflecting the changes of Yin-Yang and Water-Fire. Treatment should employ mild formulas; ancient texts recommend Heisanzi (Black Powder) and Zishuang Wan (Purple Frost Pill).
According to Qian Yi (Qian Shi): The first Bian corresponds to the Kidney, the second to the Bladder, the third to the Heart, the fourth to the Small Intestine, the fifth to the Liver, the sixth to the Gallbladder, the seventh to the Lungs, the eighth to the Large Intestine, the ninth to the Spleen, and the tenth to the Stomach. Hence, water is numbered one, starting with the Kidney. The *Bao Jian* (Treasure Mirror) states: The first Bian is the Liver, the second the Lungs, the third the Heart, the fourth the Spleen, and the fifth the Kidney. Both theories follow the inversion, counter-flow, mutual restriction, and mutual generation of the Five Elements. Generally, in Yin-Yang creation, mutual generation is smooth (Shun), while mutual restriction is inverted (Ni). Bianzheng nourishes blood and qi and promotes the mutual generation of the Five Zang organs. Mutual generation implies a mother-child relationship; mutual restriction implies a husband-wife dynamic. Generation ensures continuity; restriction ensures regulation. Fetal formation results from the balance of Water and Fire, Yin-Yang creation, and the regulation of the Five Elements, beginning with the initial emergence of Kidney Qi. However, pediatric Bianzheng involves the transformation of blood and qi, the rise and fall of Yin and Yang, and sequential maturation of the Five Zang organs, thus beginning with the Liver. Although these two views differ, each has merit and should be carefully examined.