膀胱者津液之腑。与肾为表里号曰水曹掾。又名玉海。足太阳是其经也。总通于五腑。所以五腑有疾。即
应膀胱。膀胱有疾。即应胞囊也。伤热。则小便不利。热入膀胱。则其气急。而苦小便黄涩也。膀胱寒则小便
数而清也。又石水发。则其根在膀胱。四肢瘦小。其腹胀大者是也。又膀胱。咳久不已。则传入三焦。肠满而
不欲饮食也。然上焦主心肺之病。人有热则食不入胃。寒则精神不守。泄利不止。语声不出也。实则上绝
于心气不行也。虚则引起气之于肺也。其三焦之气和。则五脏六腑皆和。逆则皆逆。膀胱中有厥阴气则
梦行不快。满胀。则小便不下。脐下重闷。或肩痛也。绝则三日气。死时鸡鸣也。其三焦之论。备云于后。
三焦者。人之三元之气也。号曰中清之腑。总领五脏六腑。荣卫经络。内外左右上下之气也。三焦通。则内
外左右上下皆通也。其于周身。灌体。和内调外。荣左养右。导上宣下。莫大于此者也。又名玉海。水道。上则
曰三管。中则名霍乱。下则曰走哺。名虽三而归一。有其名而无形者也。亦号曰孤独之腑。而卫出于上。荣
出于中。上者络脉之系也。中者经脉之系也。下者水道之系也。亦又属膀胱之宗始。主通阴阳。调虚实。呼
吸有病。则苦腹胀气满。小腹坚。溺而不得。便而窘迫也。溢则作水。留则为胀。足太阳是其经也。又上焦实
热。则额汗出。而身无汗。能食。而气不利。舌干口焦。咽闭之类。腹胀。时时胁肋痛也。寒则不入食。吐酸水。胸
背引痛。嗌干。津不纳也。实则食已还出。膨膨然不乐。虚则不能制下。遗便溺而头面肿也。中焦实热。则上
下不通。腹胀而喘咳。下气不上。上气不下。关格而不通也。寒则下痢不止。食饮不消。而中满也。虚则肠鸣
鼓胀也。下焦实热。则小便不通。而大便难苦重痛也。虚寒则大小便泄。下而不止。三焦之气和则内外和。
逆则内外逆。故云三焦者人之三元之气也。宜修养矣。
膀胱是贮存津液的腑。它与肾互为表里，被称为“水曹掾”，又名为“玉海”。足太阳膀胱经是其所属经脉，总联系着其他五腑。因此，当其他五腑有病时，就会反映到膀胱；膀胱有病时，就会反映到胞宫（子宫或精室）。若感受热邪，则小便不通利；热邪侵入膀胱，则气机急促，苦于小便黄赤涩痛。若膀胱受寒，则小便频数且清长。另外，石水病发作时，其病根在膀胱，表现为四肢消瘦细小，腹部胀大。此外，若咳嗽日久不愈，病邪会传入三焦，导致肠道胀满而不想饮食。
上焦主要主管心肺的疾病。人若有热邪，则食物无法进入胃中；若有寒邪，则精神不能内守，出现泄泻痢疾不止、声音低微甚至不出等症状。实证会导致心气运行受阻而中断；虚证则会引动肺气上逆。如果三焦之气调和，那么五脏六腑都会调和；若三焦之气逆乱，则五脏六腑皆逆乱。若膀胱中有厥阴肝经之气干扰，则多梦行走不畅；若膀胱胀满，则小便排不出，脐下沉重闷痛，或者肩部疼痛。若膀胱之气绝灭，则三日死，死亡时间多在鸡鸣时分。关于三焦的论述，详见后文。
三焦，是人体三元之气的所在，被称为“中清之腑”，总领五脏六腑、营卫经络以及内外左右上下各部位的气机。三焦通畅，则体内外、左、右、上、下全部通畅。它在周身灌注形体，调和内部与外部，滋养左侧并濡养右侧，引导上部之气宣通下部之气，没有比它更重要的了。三焦又名“玉海”、“水道”。在上部称为“三管”，在中部称为“霍乱”，在下部称为“走哺”。名称虽有三者之分，但归根结底是一体的，是有其名而无具体形态的脏腑，也被称为“孤独之腑”。卫气出于上焦，营气出于中焦。上焦是络脉系统的归属，中焦是经脉系统的归属，下焦是水道系统的归属。三焦也归属于膀胱的根本起始之处，主司通调阴阳，调节虚实。若呼吸出现病变，则会苦于腹胀气满，小腹坚硬，排尿困难，排便窘迫急迫。若水液溢出则形成水肿，停留体内则形成胀满。足太阳膀胱经是其所属经脉。
若上焦实热，则额头出汗而身体无汗，能进食但气机不利，舌干口焦，咽喉闭塞等症，伴有腹胀，时时胁肋疼痛。若上焦受寒，则不能进食，呕吐酸水，胸背牵引作痛，咽干，津液无法容纳。若上焦实证，则食物吃下后又吐出，腹部膨隆不乐；若上焦虚证，则不能制约下部，出现大小便失禁及头面部浮肿。若中焦实热，则上下气机不通，腹胀且喘咳，下气不上行，上气不下行，形成关格证而气机阻塞。若中焦受寒，则下痢不止，饮食不消化，导致中焦痞满。若中焦虚证，则肠鸣鼓胀。若下焦实热，则小便不通，大便困难且痛苦沉重疼痛。若下焦虚寒，则大小便泄泻，向下流失不止。三焦之气调和，则内外调和；三焦之气逆乱，则内外逆乱。所以说三焦是人体的三元之气，应当注重修养保养。
The Bladder is the fu-organ of Jin-Ye (body fluids). It forms an interior-exterior relationship with the Kidney, known as "Shui Cao Yuan" (Water Clerk), and is also named "Yu Hai" (Jade Sea). The Foot-Taiyang Bladder Meridian is its associated channel, which generally connects with the other five fu-organs. Therefore, when diseases occur in the other five fu-organs, they manifest in the Bladder; conversely, when the Bladder is diseased, it manifests in the Bao Luo (uterus or seminal vesicle). If injured by Heat, urination becomes difficult. If Heat enters the Bladder, Qi becomes urgent, causing distress with yellow and astringent urine. If the Bladder is Cold, urination is frequent and clear. Additionally, when Shi Shui (Stone Water) occurs, its root lies in the Bladder, characterized by emaciated limbs and a distended abdomen. Furthermore, if cough persists for a long time without resolution, the pathogen transmits to the San Jiao (Triple Burner), leading to intestinal fullness and loss of appetite.
The Upper Jiao primarily governs diseases of the Heart and Lungs. If there is Heat in the person, food cannot enter the Stomach; if there is Cold, the Spirit fails to reside within, resulting in incessant diarrhea or dysentery, and inability to speak. Excess conditions cause the Heart Qi to be blocked and unable to circulate; deficiency conditions induce Qi rebellion from the Lung. When the Qi of the San Jiao is harmonious, the Zang and Fu organs are all harmonious; if the Qi of the San Jiao rebels, all Zang and Fu organs rebel. If Jueyin Liver Qi interferes within the Bladder, one dreams of walking with difficulty; if the Bladder is full and distended, urination is obstructed, accompanied by heaviness and oppression below the umbilicus, or shoulder pain. If the Qi of the Bladder is exhausted, death occurs after three days, typically at dawn (Ji Ming). The discussion on the San Jiao follows later.
The San Jiao (Triple Burner) is the source of the Three Primal Qi in humans, known as the "Zhong Qing Zhi Fu" (Middle Clear Organ). It commands the Zang and Fu organs, Ying and Wei (Nutritive and Defensive) Qi, meridians, and the Qi throughout the body internally and externally, left and right, above and below. When the San Jiao is unobstructed, everything inside and outside, left and right, above and below, is unobstructed. In nourishing the body, harmonizing the interior and exterior, nurturing the left and right, guiding the upper to diffuse the lower, nothing surpasses this organ. It is also named "Yu Hai" (Jade Sea) and "Shui Dao" (Water Path). In the upper part, it is called "San Guan"; in the middle, "Huo Luan"; and in the lower part, "Zou Bu". Although the names differ, they return to one unity; it has a name but no distinct form, hence also called the "Gu Du Zhi Fu" (Lonely Organ). Wei Qi emerges from the Upper Jiao, and Ying Qi emerges from the Middle Jiao. The Upper Jiao belongs to the system of collateral vessels, the Middle Jiao to the system of main meridians, and the Lower Jiao to the system of water passages. It also originates from the Bladder, governing the circulation of Yin and Yang and regulating excess and deficiency. If respiration is diseased, one suffers from abdominal distension and Qi fullness, hardness of the lower abdomen, difficulty in urination, and urgency during defecation. If water overflows, edema results; if it stagnates, distension occurs. The Foot-Taiyang Bladder Meridian is its associated channel.
If the Upper Jiao has Excess Heat, sweat appears on the forehead but not on the body, appetite is present but Qi circulation is impaired, tongue is dry, mouth scorched, throat closed, accompanied by abdominal distension and occasional hypochondriac pain. If the Upper Jiao is Cold, food intake is impossible, sour water is vomited, chest and back radiate pain, throat is dry, and fluids cannot be retained. If the Upper Jiao is Excess, food is regurgitated after eating, abdomen is bloated and uncomfortable; if Deficient, it fails to control the lower orifices, leading to incontinence of stool and urine, and swelling of the head and face. If the Middle Jiao has Excess Heat, upper and lower Qi do not communicate, causing abdominal distension, wheezing, and coughing; lower Qi does not ascend, upper Qi does not descend, resulting in Guan Ge (Obstruction and Rejection) where Qi flow is blocked. If the Middle Jiao is Cold, dysentery persists, food and drink are not digested, leading to middle Jiao fullness. If the Middle Jiao is Deficient, borborygmus and drum-like distension occur. If the Lower Jiao has Excess Heat, urination is obstructed, and defecation is difficult with heavy pain. If the Lower Jiao is Deficient and Cold, both stool and urine leak downward without cessation. When the Qi of the San Jiao is harmonious, the interior and exterior are harmonious; when rebellious, the interior and exterior are rebellious. Thus, it is said that the San Jiao is the Three Primal Qi of humans, and should be cultivated and preserved.