手少阳三焦。有上中下之名。或欲以上焦附寸。中焦附关。下焦附尺。根据经言上者上之。下者下之之说。果执是说。
则如伯仁所言大小肠宜见于尺。
不宜见于寸。揆之经脉授受之次。有是理哉。大概心胞在膈上。命门在膈下三焦俱不相失而相应。上焦寄位两乳之
间。名曰膻中。中焦在胃中脘。即脐之右旁。下焦在脐下膀胱上口。故自膻中以迄脐三寸。皆为气海。有脂膜在腔子
内。包罗乎五脏六腑之外。合之胞络。共成六脏六腑。为十二经而或言腑止有五者。以三焦有名无状。不名正腑。腑属
膀胱也。而或言脏亦止五者。以命门与肾。二而一不及心胞也。然或言五腑六脏。或言五脏六腑。则六脏六腑之名不
能灭。又何疑于手少阳之为三焦。手厥阴之为胞络也哉。其体亦属相火。言其用。三焦为气之父。盖肾间气动。人之生
命。
十二经之根本。三焦者。原气之别使也。主通行三气。经历于五脏十二经。故曰。禀肾间动气以资始。藉胃中谷气以资
生。为决渎之官。水道出焉。合胞络为用。宣流气血。分别清浊。运导营卫上升下降。各得其所。脉受胞络之交。故
胞络脉。终于第四指。三焦脉。即起于无名指之端。循手腕。出臂外两骨之间。上贯肘。循 外止肩。故肩肘 臂痛。
皆三焦病。入
缺盆。布膻中。散络心胞。下膈属三焦。故病为嗌干。为喉痹。其支者。从膻中入缺盆。上项系耳后。直上出耳上角。
下颊至项。其支者。从耳后入耳中。出走耳前。交颊至目锐 。故三焦病。耳后痛。耳聋颊肿。目锐 痛。三焦之大
略如此。
手少阳三焦经，有上、中、下三个部分的名称。有人想将上焦对应于寸口脉的寸部，中焦对应于关部，下焦对应于尺部。依据《内经》“上部脉候上部病，下部脉候下部病”的说法，如果固执地采用这种观点，那么就像王叔和（字伯仁）所说的那样，大小肠的脉象应该出现在尺部，而不应该出现在寸部。但这与经脉气血流注的顺序相符吗？
大体而言，心包络位于膈肌之上，命门位于膈肌之下，三焦的功能与它们都不相违背且相互呼应。上焦的位置在两乳之间，称为膻中；中焦位于胃的中脘部位，即肚脐右侧旁开处；下焦位于肚脐以下膀胱的上口。因此，从膻中直到肚脐这三寸的区域，都称为气海。在胸腔内部有一层脂膜，包裹着五脏六腑的外部，加上胞络，共同构成六脏六腑，形成十二经脉。有人说腑只有五个，是因为三焦有名而无具体形态，不被称为正腑，而属于膀胱系统；有人说脏也只有五个，是因为命门与肾合二为一，且不单独计算心包络。然而，无论是说五腑六脏，还是说五脏六腑，“六脏六腑”的名称都不能被废除，又何必对手少阳为三焦、手厥阴为心包络产生怀疑呢？
三焦的本体属性也属于相火。论及其功能，三焦是气的父亲。因为肾间的动气发动，这是人的生命活动的根本，也是十二经脉的根本。三焦是原气的别使（分支使者），主要通行三种气，流经五脏和十二经脉。所以说，三焦禀受肾间的动气以作为生命的起始，借助胃中的水谷之气以维持生命生长。三焦被称为决渎之官（疏通水道的官员），水道由此而出。它与心包络配合发挥作用，宣通流畅气血，分别清浊之气，运导营卫之气上升下降，使各归其位。
三焦的脉象受心包络脉的影响，所以心包络的脉止于第四指（中指），而三焦的脉则起于无名指的末端，沿着手腕，出于手臂外侧两骨之间，向上穿过肘部，沿着臂外侧到达肩部。因此，肩、肘、臂部的疼痛，都是三焦的病证。三焦经脉进入缺盆，分布于膻中，散布联络心包络，向下穿过膈肌，归属于三焦。所以三焦有病会出现咽喉干燥、喉痹的症状。其支脉，从膻中进入缺盆，上行颈部，联系耳后，直上出耳上角，下行至面颊到颈部。另一支脉，从耳后进入耳中，走出耳前，经过面颊到达目外眦。所以三焦有病，会出现耳后痛、耳聋、面颊肿、目外眦痛等症状。三焦的大致情况就是这样。
The Hand-Shaoyang Sanjiao (Triple Burner) meridian is named according to its upper, middle, and lower sections. Some propose that the Upper Jiao corresponds to the Cun (Inch) position of the radial pulse, the Middle Jiao to the Guan (Bar) position, and the Lower Jiao to the Chi (Cubit) position. Relying on the classic saying "upper [pulse] reflects upper [pathology], lower [pulse] reflects lower [pathology]," if one rigidly adheres to this view, then as Wang Shuhe (courtesy name Boren) stated, the pulses of the Large Intestine and Small Intestine should be found at the Chi position, not at the Cun position. Does this align with the sequence of meridian transmission?
Generally speaking, the Pericardium (Xinbao) is located above the diaphragm, while the Mingmen (Gate of Life) is below it; the functions of the Sanjiao are consistent with and correspond to both. The Upper Jiao resides between the two breasts and is named Danzhong (Chest Center). The Middle Jiao is located at the Zhongwan point in the stomach, which is beside the right side of the umbilicus. The Lower Jiao is located below the umbilicus at the upper opening of the Bladder. Therefore, the area from Danzhong down to three cun above the umbilicus is all referred to as the Sea of Qi (Qihai). Inside the thoracic cavity, there is a layer of fatty membrane that envelops the exterior of the Zang and Fu organs. Combined with the Pericardium, they form six Zang and six Fu organs, constituting the twelve meridians. Some say there are only five Fu organs because the Sanjiao has a name but no distinct shape, so it is not considered a principal Fu organ, but rather belongs to the category of the Bladder. Others say there are only five Zang organs because the Mingmen and Kidney are treated as one, excluding the Pericardium. However, whether one speaks of five Fu and six Zang, or five Zang and six Fu, the designation of "six Zang and six Fu" cannot be abolished. Thus, why doubt that the Hand-Shaoyang is the Sanjiao and the Hand-Jueyin is the Pericardium?
Its substance also pertains to Ministerial Fire (Xianghuo). Regarding its function, the Sanjiao is the father of Qi. This is because the vital movement of Qi in the Kidneys initiates human life and serves as the root of the twelve meridians. The Sanjiao is the special envoy of Yuan Qi (Original Qi), primarily responsible for circulating the three types of Qi through the five Zang organs and twelve meridians. Hence, it is said: "It receives the vital movement of Qi from the Kidneys to initiate existence, and relies on the Grain Qi from the Stomach to sustain growth." It is called the Official of Dredging (Juedu), through which water passages flow. It works in conjunction with the Pericardium to disseminate and circulate Blood and Qi, separate clear from turbid, and guide Ying (Nutrient) and Wei (Defensive) Qi to ascend and descend, allowing each to reach its proper place.
The pulse of the Sanjiao is influenced by the Pericardium pulse; thus, the Pericardium pulse terminates at the fourth finger (middle finger), while the Sanjiao pulse originates at the tip of the ring finger. It follows the wrist, emerges between the two bones on the lateral aspect of the arm, passes up through the elbow, follows the lateral arm to the shoulder. Therefore, pain in the shoulder, elbow, and arm are all diseases of the Sanjiao. It enters the Key Valley (Quepen), distributes in the Danzhong, scatters and connects with the Pericardium, descends through the diaphragm, and belongs to the Sanjiao. Thus, disease in the Sanjiao manifests as dryness of the throat and Bi syndrome of the throat. Its branch vessel enters the Key Valley from the Danzhong, ascends the neck, connects behind the ear, goes straight up to emerge above the ear angle, and descends along the cheek to the neck. Another branch enters the ear from behind the ear, exits in front of the ear, crosses the cheek, and reaches the outer canthus of the eye. Therefore, Sanjiao disease presents with pain behind the ear, deafness, swelling of the cheek, and pain at the outer canthus of the eye. Such is the general overview of the Sanjiao.