七牢者。阴也。指下寻之即无。按之即有。曰牢。主骨间疼痛。气居于表。
七牢者。阴也。震之象也。震为雷。云岐子谓其有水火相乘之气。今指下
寻之即无。按之即有曰牢。牢者坚牢也。其脉沉弦有力。动而不移。乃病
根深痼。而成不拔之势也。指下寻之即无。表虚也。按之即有。里实也。所
谓里实者。邪气实。所谓表虚者。正气虚也。在内之邪气固。则水火相煎。
故骨间疼痛。在外之正气虚。则血不外荣。而气独居于表。
按脉经第一篇。有革脉而无牢脉。千金翼以革为牢。其脉经则曰革脉
有似沉伏。实大而长。微弦。
脉入皮肤辨息难。时时气促在胸前。只缘水火相刑克。欲待痊除更问天。
脉入皮肤。则轻手于皮肤之上。不见其脉。即前指下寻之即无也。凡脉
有往来。则辨息易矣。今云辨息难言。按之即有。而且坚牢不移其处。及
举之皮肤之间。不见其有脉。夫肺为华盖。乃五脏六腑之首。居于胸中。
主气而司呼吸者也。今肺气衰。则火来乘之。木来薄之。水者。金之子。所
以制火者也。今金气衰。则不能生水。火反乘金之势。而煎熬其水。犹釜
底之薪燔。而釜中之水涸也。时时气促者。只缘水火交战于胸中。互相
刑克呼虽出于心肺。吸不得归于肾肝。故时时气促也。即经云。不及则
所胜妄行。所生受病。所不胜薄之也。由此观之。四大分张。五行乖乱。欲
望其痊除也难矣。
按脉经云。平三关病候。并治宜。第三篇内寸口无牢脉。于关部则曰关
脉牢。脾胃气塞盛热。则腹中响。响宜服紫菀丸。渴脾丸。针灸胃营泻之。
于尺部。则曰尺脉牢。腹满。阴中急。宜服葶苈子茱萸丸。针关元丹田中
极。
七牢脉，属于阴脉。手指轻寻（轻轻探查）时感觉不到脉搏，重按时才能感觉到，这种脉象称为“牢”脉。它主要主骨间疼痛。这是因为正气虚弱而居于体表。
所谓七牢脉，属于阴脉，具有震卦的意象。震卦象征雷。云岐子认为它具有水火相互乘侮的气机特点。现在手指轻寻时感觉不到脉搏，重按时才感觉到，这就叫“牢”。牢，意为坚固牢固。其脉象沉、弦且有力，跳动位置固定不移。这是病根深重顽固，形成了不可动摇的局势。手指轻寻时感觉不到，说明表虚；重按时能感觉到，说明里实。所谓的“里实”，是指邪气盛实；所谓的“表虚”，是指正气虚弱。体内的邪气固结，就会导致水火相互煎熬，所以出现骨间疼痛。体表的正气虚弱，血液就不能外达以荣养肌肤，导致气独存于体表。
查阅《脉经》第一篇，只有“革脉”而没有“牢脉”。《千金翼方》将革脉视为牢脉。但《脉经》中说革脉似乎有沉伏之象，实际上大而长，微带弦象。
脉象出现在皮肤表层，辨别呼吸变得困难，时常气短胸闷在胸前。这仅仅是因为水火相互刑克。想要痊愈消除病症，只能问天了。
脉象浮越于皮肤表面，则轻手在皮肤之上，看不见脉搏，就是前面所说的“手指轻寻时感觉不到”。凡是脉搏有往来起伏，辨别呼吸就容易了。现在说“辨别呼吸困难”，是因为重按时脉搏存在，而且坚固牢固、位置不移，举取（轻按）在皮肤之间时，又看不见脉搏。肺为华盖，是五脏六腑之首，居于胸中，主管气并司理呼吸。现在肺气衰弱，火气就来乘袭它，木气就来侵薄它。水是金之子，是用来制约火的。现在金气衰弱，就不能生水，火反而乘袭金的势力，从而煎熬水液，就像锅底柴火烧得旺盛，锅中的水被烧干一样。时常气短，仅仅是因为水火在胸中交战，互相刑克。呼虽然出于心肺，吸却不得归于肾肝，所以时常气短。正如经文所说：不及（虚弱），则所胜者妄行，所生者受病，所不胜者侵薄它。由此看来，四大（地水火风）分离张散，五行乖违混乱，想要指望它痊愈，很难啊。
查阅《脉经》说，平诊三关的病候，以及治疗适宜的方法。第三篇内寸口没有牢脉，在关部则说关脉牢，脾胃气机阻塞，盛热，则腹中作响，响宜服用紫菀丸、渴脾丸，针灸胃营穴用泻法。在尺部，则说尺脉牢，腹部胀满，阴部拘急，宜服用葶苈子茱萸丸，针刺关元、丹田、中极穴。
Seven "Lao" (Firm) pulses belong to Yin. When seeking with light pressure, the pulse is imperceptible; when pressing deeply, it becomes palpable. This is called "Lao". It primarily indicates pain between the bones. Qi resides on the exterior.
The so-called Seven "Lao" pulse belongs to Yin and embodies the image of Zhen (Thunder). Zhen represents Thunder. Yun Qizi stated that it possesses the qi of water and fire mutually overcoming each other. Now, when seeking with light pressure, the pulse is imperceptible; when pressing deeply, it becomes palpable. This is called "Lao". Lao means firm and solid. The pulse is deep (Chen), wiry (Xian), and forceful, moving without shifting position. This indicates a deep-rooted and stubborn disease, forming an unshakable situation. Imperceptibility under light pressure indicates Exterior Deficiency (Biao Xu); palpability under deep pressure indicates Interior Excess (Li Shi). The so-called "Interior Excess" refers to the excess of pathogenic factors; the so-called "Exterior Deficiency" refers to the deficiency of healthy qi. When pathogenic factors inside are consolidated, water and fire fry each other, hence causing pain between the bones. When healthy qi outside is deficient, blood cannot nourish the exterior, leaving qi alone residing on the surface.
According to the first chapter of *Mai Jing* (Pulse Classic), there is a "Ge" (Leather) pulse but no "Lao" pulse. *Qianjin Yi* treats Ge as Lao. However, *Mai Jing* states that the Ge pulse seems sunken and hidden, yet is actually large, long, and slightly wiry.
When the pulse enters the skin, distinguishing respiration becomes difficult, with frequent shortness of breath in the chest. This is solely due to water and fire mutually punishing and overcoming each other. To hope for recovery is to ask heaven.
When the pulse enters the skin, meaning it is not visible upon light touch above the skin, this corresponds to the previously mentioned "imperceptible under light pressure." Whenever a pulse has coming and going, distinguishing respiration is easy. Now, saying "distinguishing respiration is difficult" implies that upon deep pressure, the pulse exists and is firm and immovable, yet upon lifting (light pressure) at the skin level, no pulse is seen. The Lung is the Canopy of Flowers, the head of the five zang and six fu organs, residing in the chest, governing qi and controlling respiration. Now, if Lung qi declines, Fire comes to overcome it, and Wood comes to encroach upon it. Water is the child of Metal and serves to control Fire. Now, if Metal qi declines, it cannot generate Water; Fire instead overcomes Metal's momentum, thereby frying the Water, just like fuel burning fiercely at the bottom of a pot while the water inside dries up. Frequent shortness of breath occurs solely because water and fire battle in the chest, mutually punishing each other. Exhalation originates from the Heart and Lung, but inhalation fails to return to the Kidney and Liver, hence frequent shortness of breath. As the classics state: If insufficient, the element that overcomes it acts recklessly, the element it generates suffers disease, and the element that overcomes it encroaches. From this perspective, the Four Great Elements separate and scatter, the Five Phases become chaotic and disordered. To hope for recovery is indeed difficult.
According to *Mai Jing*, regarding the pathological conditions of the three positions and suitable treatments: In the third chapter, there is no Lao pulse at the Cun Kou (inch position). At the Guan (bar) position, it says: Guan pulse is Lao, indicating Spleen and Stomach qi obstruction with excessive heat, causing rumbling in the abdomen. For rumbling, one should take Zi Wan Wan (Aster Pill) or Ke Pi Wan (Thirst-Spleen Pill), and needle the Wei Ying point using the reducing method. At the Chi (cubit) position, it says: Chi pulse is Lao, indicating abdominal fullness and urgency in the yin region. One should take Ting Li Zi Zhu Yu Wan (Semen Lepidii Fructus and Cornus Pill), and needle Guan Yuan, Dan Tian, and Zhong Ji points.