壮者之气血盛，其肌肉滑，气道通，荣卫之行，不失其常，故昼精而夜瞑。老者之气血衰，其肌肉枯，
气道涩，五脏之气相搏，其荣气衰少，而卫气内伐，故昼不精，夜不瞑也。（出营卫生会篇。）
人与天地相应，日月相参，故虽平居，其腠理开闭缓急，故常有时也。月满，则海水西盛，人气血精，
肌肉充，皮肤致，毛发坚，腠理 ，烟垢着。当是之时，虽遇贼风，其入浅不深。月郭空，则海水东盛，人气
血虚，卫气去，形独居，肌肉减，皮肤纵，腠理开，毛发残， 理薄，（ 同焦。）烟垢落。
当是之时，遇贼风，则其入深，其病卒暴。故得三虚者，其死暴疾，得三实者，邪不能伤人也。乘年之衰，
（本命受流年克制。）逢月之空，（月魄。）失时之和，（寒温非时。）是为三虚；逢年之
盛，遇月之满，得时之和，是为三实。（上《灵枢》。）
天温日明，则人血淖液而卫气浮，故血易泻，气易行。天寒日阴，则人血凝泣而卫气沉。月始生，则
血气始精，卫气始行。月郭满，则血气实，肌肉坚。月郭空，则肌肉减，
经络虚，卫气去，形独居。是以天寒无刺，天温无疑，（行之无忌。）月生无泻，月满无补，月郭空无治，
是谓得时而调之。
阳气者，一日而主外，（日，言昼也。）平旦人气生，日中而阳气隆，日西而阳气已虚，气门乃闭，是
故暮而收拒，无扰筋骨，无见雾露，反此三时，形乃困薄。（上《素问》。薄，迫也，削也。）
气阳而应日，血阴而应月。故暑则气泻，寒则气敛，日中则气壮，日下则气衰。所谓日中得病夜半愈，夜
半得病日中愈者，阴阳乘除故也。月生人血渐盛，月死人血渐减。凡病在血分及失血诸证，有血盛邪无所容而
病退者，有血减邪失所附而病亦退者。若夫精神之复，必在生明之候矣。故仲景于疟疾曰∶以月一日发，当
十五日愈。设不瘥，当月尽解。疟为卫邪入荣之病，故以晦朔决瘥剧之期也。昔尝患暑下血，以月满得病，血
止后，神明不复，至次月朔日，顿见爽朗矣。世俗谓久病以朔望病势增损定吉凶，岂诬也哉。
经脉血气，似于形诊无关。《灵枢》曰∶营气之病也，血上下行。东垣谓∶血上下行者，面部乍肥乍
瘦也。血随气升，即面 而似肥。血随气降，即面消而似瘦。元气不足之人，常有此象。又曰∶营气霈然
者，病在血脉。是邪气激其血脉，光泽浮越于面部也。观此，岂真无关形诊耶。
身体强健之人的气血充盛，肌肉滑润，气道通畅，营气与卫气的运行不失常态，所以白天精神饱满，夜晚睡眠安稳。年老之人的气血衰退，肌肉枯槁，气道涩滞，五脏之气相互搏结，其营气衰少，而卫气向内侵扰，所以白天精神不振，夜晚难以入睡。（出自《灵枢·营卫生会》篇。）
人与天地相应，与日月相参合，所以即使平时居住，腠理的开闭缓急也常有定时。月亮圆满时，海水向西涨盛，人气血精微充盈，肌肉充实，皮肤致密，毛发坚挺，腠理闭合，烟垢附着。在这个时候，即使遇到贼风（不正之风），邪气侵入浅而不深。月亮亏缺时，海水向东涨盛，人气血虚弱，卫气离去，形体独自存在，肌肉消瘦，皮肤松弛，腠理开泄，毛发残落，纹理薄弱（“”同“焦”），烟垢脱落。在这个时候，如果遇到贼风，邪气侵入深，疾病突然发作且猛烈。所以得到“三虚”的人，死亡迅速且突发；得到“三实”的人，邪气不能伤害人体。逢上年份的衰弱（本命受流年克制），遇到月亮的亏空（月魄不足），失去时令的和谐（寒温不合时宜），这叫做“三虚”；逢上年份的旺盛，遇到月亮的圆满，得到时令的和谐，这叫做“三实”。（以上出自《灵枢》。）
天气温暖日照明亮，则人血液稀薄流动，卫气浮越于表，所以血液容易泻出，气机容易运行。天气寒冷日照阴暗，则人血液凝滞不畅，卫气沉伏于里。月亮初生时，血气开始精微，卫气开始运行。月亮圆满时，血气充实，肌肉坚实。月亮亏缺时，肌肉消瘦，经络空虚，卫气离去，形体独自存在。因此天气寒冷时不要针刺，天气温暖时无需疑虑（行针无禁忌）。月亮初生时不可用泻法，月亮圆满时不可用补法，月亮亏缺时不宜治疗，这叫做顺应时节来调治。
阳气在一天之中主司体表（日，指白天），清晨人气生发，中午阳气最隆盛，傍晚阳气已虚，汗孔关闭，所以暮夜应当收敛拒邪，不要扰动筋骨，不要接触雾露，违背这三个时辰的规律，身形就会困顿薄弱。（以上出自《素问》。薄，意为逼迫、削减。）
气属阳而对应太阳，血属阴而对应月亮。所以暑热则气外泄，寒冷则气内收，中午则气壮盛，日落则气衰减。所谓中午得病半夜痊愈，半夜得病中午痊愈的，是因为阴阳消长平衡的缘故。月亮初生时人血逐渐旺盛，月亮死绝时人血逐渐减少。凡是病在血分及失血的各种证候，有血盛时邪气无处容身而病退的，有血减时邪气失去依附而病也退的。至于精神的恢复，一定是在月亮由缺变圆的时候。所以张仲景对于疟疾说：如果在初一发病，应当在十五痊愈。如果不好转，应当在月底解除。疟疾是卫分之邪进入营分的病，所以根据晦朔（农历每月的最后一天和第一天）来判断痊愈或加重的时期。过去我曾患暑热导致的便血，在月圆时得病，血止后，神志不清，直到下个月初一那天，顿时感到神清气爽了。世俗认为久病在朔望之日病情增减可定吉凶，这难道是诬妄的吗？
经脉血气似乎与形诊无关。《灵枢》说：营气病变，表现为血上下逆行。李东垣说：血上下逆行的表现，是面部忽胖忽瘦。血随气上升，即面部浮肿似胖。血随气下降，即面部消瘦似瘦。元气不足的人，常有这种征象。又说：营气充沛外溢的，病在血脉。这是邪气激荡血脉，光泽浮越于面部的表现。观察这些，难道真的与形诊无关吗？
The qi and blood of the vigorous are abundant; their muscles are smooth, their qi pathways are unobstructed, and the movement of Ying Qi (Nutrient Qi) and Wei Qi (Defensive Qi) follows its normal course. Therefore, they are alert during the day and sleep soundly at night. The qi and blood of the elderly decline; their muscles become withered, their qi pathways become obstructed, the qi of the Five Zang Organs clashes with one another, their Ying Qi becomes deficient and scanty, and Wei Qi invades inward. Therefore, they lack vitality during the day and suffer from insomnia at night. (From the chapter "Ying Sheng Hui" of *Ling Shu*.)
Humans correspond to Heaven and Earth and participate in the cycles of the Sun and Moon. Thus, even in daily life, the opening and closing of Cou Li (interstices/skin pores) have their regular timing. When the moon is full, the seawater swells toward the west, human blood and essence become abundant, muscles are filled, skin is dense, hair is firm, Cou Li are closed, and dust adheres. At this time, even if one encounters Wind Pathogens (evil winds), the invasion is shallow and not deep. When the moon wanes, the seawater swells toward the east, human blood and qi become deficient, Wei Qi departs, leaving only the physical form; muscles diminish, skin becomes lax, Cou Li open, hair falls out, the texture becomes thin (" " is identical to "Jiao"), and dust falls off. At this time, encountering evil winds leads to deep invasion and sudden, violent illness. Therefore, those who encounter the "Three Deficiencies" die suddenly and rapidly; those who encounter the "Three Excesses" are not harmed by pathogens. Encountering the decline of the year (where the natal element is controlled by the annual element), meeting the emptiness of the moon (waning moon), and losing the harmony of the season (inhospitable cold or heat) constitute the "Three Deficiencies"; encountering the prosperity of the year, meeting the fullness of the moon, and obtaining the harmony of the season constitute the "Three Excesses". (Above from *Ling Shu*.)
When the weather is warm and the sun is bright, human blood becomes fluid and Wei Qi floats on the surface; thus, blood is easily dispersed, and qi moves freely. When the weather is cold and the sun is obscured, human blood coagulates and stagnates, and Wei Qi sinks inward. When the moon begins to grow, blood and qi begin to refine, and Wei Qi begins to circulate. When the moon is full, blood and qi are substantial, and muscles are firm. When the moon is empty (waning/new), muscles diminish, meridians are deficient, Wei Qi departs, and only the form remains. Therefore, when the weather is cold, do not use acupuncture; when the weather is warm, there is no need for hesitation (no taboos in treatment). When the moon is growing, do not use draining methods; when the moon is full, do not use tonifying methods; when the moon is empty, do not treat. This is called regulating according to the appropriate time.
Yang Qi governs the exterior throughout the day. At dawn, Human Qi arises; at noon, Yang Qi is most prosperous; at sunset, Yang Qi is already deficient, and the Qi Gates (pores) close. Therefore, in the evening, one should conserve and repel pathogens, not disturb the sinews and bones, and avoid exposure to fog and dew. Reversing these three periods causes the physical form to become exhausted and weakened. (Above from *Su Wen*. "Bo" means pressing or diminishing.)
Qi is Yang and corresponds to the Sun; Blood is Yin and corresponds to the Moon. Therefore, summer heat causes Qi to disperse, cold causes Qi to contract, midday makes Qi strong, and dusk makes Qi decline. The reason why diseases contracted at midday heal at midnight, and diseases contracted at midnight heal at midday, is due to the mutual substitution of Yin and Yang. When the moon grows, human blood gradually increases; when the moon dies (wanes), human blood gradually decreases. In all cases where disease resides in the Blood aspect or involves various hemorrhagic syndromes, there are instances where abundant blood leaves no room for pathogens, causing the disease to recede, and instances where diminished blood deprives pathogens of attachment, also causing the disease to recede. As for the recovery of spirit, it must occur during the phase of the waxing moon. Therefore, Zhang Zhongjing stated regarding Malaria (Nue Ji): If it starts on the first day of the lunar month, it should heal on the fifteenth. If it does not improve, it should resolve by the end of the month. Malaria is a disease where Wei Pathogens enter the Ying level; thus, the dates of Hui (last day of lunar month) and Shuo (first day of lunar month) determine the period of remission or exacerbation. I once suffered from hematochezia due to summer heat. I contracted the illness during the full moon. After the bleeding stopped, my spirit remained confused, but on the first day of the following month (Shuo), I suddenly felt clear-headed. Is it false that secular beliefs hold that the prognosis of chronic illnesses can be determined by the fluctuations in condition on the days of Shuo and Wang (full moon)?
Meridian blood and qi seem unrelated to Xing Zhen (observation of physical signs). *Ling Shu* states: In diseases of Ying Qi, blood flows up and down. Li Dongyuan said: The manifestation of blood flowing up and down is the face appearing alternately fat and thin. When blood rises with Qi, the face appears swollen like being fat; when blood descends with Qi, the face appears emaciated like being thin. People with insufficient Yuan Qi often exhibit this sign. It is also said: When Ying Qi is abundant and overflowing, the disease is in the blood vessels. This is because pathogens agitate the blood vessels, causing luster to float to the surface of the face. Observing this, how can it truly be said to be unrelated to Xing Zhen?