少气而虚。任督为腹背中行。有血气之分。故其所苦如此。脊强内结。是其在阳在阴之异。冲脉者。十二经之海。邪客
之则逆气特剧。带脉者。在季胁而横束诸脉。故有病焉。则弛纵而腰间溶溶。其经系足少阳。故阴中之阳失其守。则气
少如坐水中。盖此八脉病形。在内经散出诸篇。若无统属。故越人并取发难。二十七难至此三篇。通言奇经。详且尽矣。
（第三十旧同）难曰。荣气之行。常与卫气相随不。然。经言人受气（生气）于谷。（五味）谷入于胃。乃传与五脏
六腑。五脏六腑。皆受于气。（水谷之精）其清（阳）者（训处下同）为荣（血）浊（阴）者为卫（气）荣行脉中。卫行
脉外。荣周不息。五十（度）而复大会。（手太阴寸口）阴阳相贯。如环之无端。故知荣卫相随也。
按此难问答。据灵枢荣卫生会篇文。而明荣卫不相离之义。然谓卫气。其义不一。如卫气篇。卫气行篇。则谓独行
之卫也。生会篇则谓并行之卫也。凡诸邪在脉外者。皆属此卫气之分。故曰荣行脉中。卫行脉外。各有其经所属之部分
焉。不则。何以有中风是太阳卫病。以桂枝。伤寒是太阳荣病。以麻黄等语乎。若夫浮散之卫。则昼行诸阳。夜行诸阴。
此难大意。专据一脉有二病之变。以明荣卫相随之义。前篇所谓是动所生二病。亦因是推之。则可矣。荣卫清浊之义。
旧注详尽。其说盖 血气互根之理尔。
气息短少且身体虚弱。任脉和督脉位于腹部和背部的正中线上，有血与气的区分，所以它们所导致的痛苦是这样的。脊柱僵硬且内部结聚，这是病在阳经或阴经的不同表现。冲脉是十二经脉的海汇之处，邪气侵袭它，就会导致逆气特别剧烈。带脉位于季胁部位，横向约束各条经脉，所以一旦患病，就会出现腰部松弛无力、软绵绵的感觉。带脉的经络联系足少阳胆经，所以当阴中之阳失去守持时，就会感到气短，如同坐在水中一样。大概这八条奇经的病证形态，在《内经》中散见于各个篇章，如果没有统一的归属，所以越人（秦越人/扁鹊）一并提出疑问进行阐发。从第二十七难到这三篇，通篇论述奇经，详细而全面了。（第三十难原文相同）
问：营气的运行，总是随着卫气一起吗？
答：经文说，人从饮食谷物中摄取生气。谷物进入胃中，就传送给五脏六腑。五脏六腑都接受这些气（水谷的精微物质）。其中清轻的部分（属阳）成为营气（行于脉中的血液成分），重浊的部分（属阴）成为卫气（行于脉外的防御之气）。营气在脉管中运行，卫气在脉管外运行，营气周流不息，每五十个循环周期后重新大会合于手太阴肺经的寸口部位。阴阳经脉相互贯通，像圆环一样没有尽头，因此知道营气和卫气是相随运行的。
按语：这个问答依据《灵枢·营卫生会》篇的文字，来阐明营卫不相分离的道理。然而关于卫气的含义，说法不一。如《卫气》篇、《卫气行》篇，说的是独自运行的卫气；《营卫生会》篇则说的是并行运行的卫气。凡是各种邪气在脉外的，都属于这种卫气的范畴，所以说“营行脉中，卫行脉外”，各自有其所属的经络部分。否则，怎么会有“中风是太阳经卫分病，用桂枝汤治疗；伤寒是太阳经营分病，用麻黄汤治疗”这样的说法呢？至于那种浮散不定的卫气，则是白天运行于诸阳经，夜晚运行于诸阴经。这一难的大意，专门依据一条经脉有两种病变的变理，来阐明营卫相随行的意义。前一篇所说的“是动”和“所生”两种病证，也可以由此推演出来。关于营卫清浊的含义，旧有的注释已经非常详尽，其学说大概是基于气血互根的原理罢了。
Shortness of breath and deficiency. The Ren Mai (Conception Vessel) and Du Mai (Governing Vessel) run along the midline of the abdomen and back, having distinctions between blood and qi; thus, their afflictions manifest in this manner. Stiffness of the spine with internal knotting indicates differences between pathology in the Yang meridians and Yin meridians. The Chong Mai (Penetrating Vessel) is the sea of the twelve regular meridians; when pathogenic factors invade it, rebellious qi becomes particularly severe. The Dai Mai (Girdle Vessel) is located at the costal margin and horizontally binds all meridians; therefore, when diseased, it causes flaccidity and a sensation of looseness in the waist region. Its meridian connects to the Foot-Shaoyang Gallbladder Meridian; thus, when the Yang within Yin loses its guardianship, there is a shortage of qi, resembling the feeling of sitting in water. Generally, the pathological manifestations of these eight extraordinary vessels are scattered across various chapters of the *Neijing* (*Inner Canon*) without unified classification. Therefore, Yue Ren (Qin Yueren/Bian Que) raised questions collectively to elucidate them. From the Twenty-Seventh Difficulty through these three sections, the discussion covers the extraordinary vessels comprehensively and thoroughly. (The Thirtieth Difficulty is identical to the old text.)
Question: Does the movement of Ying Qi (Nutritive Qi) always accompany Wei Qi (Defensive Qi)?
Answer: The classics state that humans derive Sheng Qi (Vital Qi) from grain. When grain enters the stomach, it is transmitted to the Zang organs and Fu organs. All Zang and Fu organs receive this Qi (the essence of water and grain). The clear portion (Yang) becomes Ying Qi (blood component circulating within vessels), while the turbid portion (Yin) becomes Wei Qi (defensive qi circulating outside vessels). Ying Qi circulates within the vessels, and Wei Qi circulates outside the vessels. Ying Qi flows continuously, completing fifty cycles before reconvening at the Cun Kou (Cun position) of the Hand-Taiyin Lung Meridian. Yin and Yang meridians interconnect like an endless circle; thus, we know that Ying Qi and Wei Qi move together.
Commentary: This dialogue is based on the text of the *Lingshu* chapter "Ying Wei Sheng Hui" to clarify the principle that Ying and Wei Qi do not separate. However, the meaning of Wei Qi varies. In the chapters "Wei Qi" and "Wei Qi Xing," it refers to Wei Qi that moves independently; in the chapter "Ying Wei Sheng Hui," it refers to Wei Qi that moves concurrently. All pathogenic factors located outside the vessels belong to this category of Wei Qi. Hence, it is said that "Ying Qi moves within the vessels, and Wei Qi moves outside the vessels," each having its specific meridian distribution. Otherwise, how could one explain statements such as "Wind-stroke is a disease of the Taiyang Wei aspect, treated with Guizhi Tang (Cinnamon Twig Decoction); Cold damage is a disease of the Taiyang Ying aspect, treated with Mahuang Tang (Ephedra Decoction)"? As for the floating and dispersed Wei Qi, it travels through the Yang meridians during the day and the Yin meridians at night. The main point of this Difficulty focuses specifically on the variations of two diseases within one vessel to illustrate the accompanying nature of Ying and Wei Qi. The two types of diseases mentioned in the previous section, namely "Shi Dong" (Is-Moving) and "Suo Sheng" (So-Produced), can also be deduced from this reasoning. Previous annotations regarding the clarity and turbidity of Ying and Wei Qi are already quite detailed; their theory is essentially based on the principle of mutual root between Blood and Qi.