既视其口。当察其唇。唇也者。齿之垣也。脾之官也。肌肉之本也。经曰。脾者。谏议之官。知周出焉。其充在肌。
其华在唇。故视唇之好恶。可知脾之吉凶。何则。黄色小理者脾小。粗理者脾大。揭唇者脾高。唇下纵者脾
下。唇坚者脾坚。唇大而不坚者脾脆。唇上下好者脾端正。唇偏举者脾偏倾。此形容之常也。左病者应在
左。右病者应在右。上应乎上。下应乎下。而凡形容之变。气色之殊。皆可以是推之。此部位之分也。按部位
而视形容。则唇肿者。病气实。唇痿者。形气虚。唇短缩者。脾伤。唇不收者。脾病。唇烂者。阳明之证。唇反者。太
阴之终。唇焦干者。病在肉。唇枯槁者。病在脾。唇疮者。邪从外解。唇裂者。毒从内发。唇内生疮者。腹中有虫。
唇上碎裂者。胃经有热。唇口僻者。风中阳明之筋。唇口撮者。风入阳明之脉。诸太过者。病在外。诸不及者。
病在内。此皆形容之变也。视形容而观气色。则唇赤者。常色也。深赤者。为太过。淡红者。为不及。淡白而黑
者。寒甚。深赤而黯者。热深。青而深者。主痛。青而淡者。为寒。唇白者。脾亏。唇黄者。脾病。诸色浅者。正气虚。
诸色深者。邪气实。明润而有血色者生。枯暗而无血色者死。此皆气色之殊也。夫分形容气色而言之。所以
识其常。合形容气色而观之。所以通其变。然究其常变。而原其始终。体用虽殊。莫不以神为本。夫神也者。
明润精爽。而有血色者也。得则生。失则死。易传云。精气为物。游魂为变。是故知鬼神之情状。其死生之谓乎。
已经观察了口部，接下来应当审视嘴唇。唇，是牙齿的屏障，是脾的外候，也是肌肉的根本所在。《内经》说：“脾，如同谏议之官，智慧周遍由此而出。”脾的功能充养于肌肉，其荣华显露于嘴唇。因此，通过观察嘴唇的好与坏，可以推断脾脏的吉凶状况。为什么呢？因为：唇纹细密者，脾脏较小；唇纹粗糙者，脾脏较大；嘴唇上翻者，脾脏位置偏高；嘴唇下垂松弛者，脾脏位置偏低；嘴唇坚实者，脾脏坚固；嘴唇虽大但不坚实者，脾脏脆弱；嘴唇上下形态匀称协调者，脾脏位置端正；嘴唇偏向一侧隆起者，脾脏位置偏斜。这些都是唇形描述的常规情况。左侧病变，反应在左侧；右侧病变，反应在右侧；上部对应上部，下部对应下部。凡是唇形的变化、气色的差异，都可以据此进行推演。这是部位对应的划分。按照部位观察唇形，则：嘴唇肿胀者，病邪气实；嘴唇萎缩者，形体之气虚；嘴唇短缩者，脾脏受损；嘴唇不能收拢者，脾脏患病；嘴唇溃烂者，属阳明经证候；嘴唇外翻者，属太阴经病证的终末期；嘴唇焦干者，病在肌肉；嘴唇枯槁者，病在脾脏；嘴唇生疮者，邪气从外部解除；嘴唇裂开者，毒邪从内部发出；嘴唇内侧生疮者，腹中有寄生虫；嘴唇上方碎裂者，胃经有热；口角歪斜者，风邪中伤阳明经的筋脉；口唇撮急（紧缩）者，风邪侵入阳明经的脉络。所有表现过于亢盛的，病邪在外；所有表现不足的，病邪在内。这些都是唇形变化的表现。通过观察唇形再结合气色来看，则：嘴唇红润者，是正常的颜色；深红色者，为阳气太过；淡红色者，为阳气不及；淡白而发黑者，寒邪极盛；深赤而暗滞者，热邪深入；青色且深沉者，主疼痛；青色且浅淡者，为寒证。嘴唇白色者，脾脏亏虚；嘴唇黄色者，脾脏有病。所有颜色浅淡者，正气虚弱；所有颜色深重者，邪气实盛。色泽明润且有血色者，预后良好（生）；色泽枯暗而无血色者，预后不良（死）。这些都是气色的差异。分别论述唇形和气色，是为了识别正常状态；综合唇形和气色来观察，是为了通晓异常变化。然而，探究常态与变态，追溯疾病的始终，虽然体用不同，但无不以“神”为根本。所谓“神”，是指面色明润精爽，且有血色的表现。得神则生，失神则死。《易经·系辞传》说：“精气凝聚形成万物，游魂变化导致变异，因此能知晓鬼神的情状。”这说的就是生死的变化规律吧。
Having observed the mouth, one should then examine the lips. The lips serve as the wall of the teeth, are the external manifestation of the Spleen (Pi), and constitute the root of the muscles. The Classics state: "The Spleen is like an official of remonstrance, from which wisdom and comprehensive knowledge emerge." Its function nourishes the muscles, and its brilliance manifests in the lips. Therefore, by observing the condition of the lips, one can deduce the auspiciousness or inauspiciousness of the Spleen. Why is this so? Because: fine lip texture indicates a small Spleen; coarse lip texture indicates a large Spleen; everted lips indicate a high-positioned Spleen; drooping lower lips indicate a low-positioned Spleen; firm lips indicate a solid Spleen; large but non-firm lips indicate a fragile Spleen; symmetrical upper and lower lips indicate a centrally positioned Spleen; unilateral protrusion of the lips indicates a tilted Spleen. These are the standard descriptions of lip morphology. Disease on the left corresponds to the left side; disease on the right corresponds to the right side; the upper corresponds to the upper, and the lower to the lower. Any variations in morphology and differences in complexion can be inferred through these principles. This constitutes the division of anatomical correspondence. By observing morphology according to location: lip swelling indicates excess pathogenic Qi; lip atrophy indicates deficiency of form and Qi; shortening of the lips indicates injury to the Spleen; inability to close the lips indicates Spleen disease; ulceration of the lips indicates a Yangming (Stomach/Large Intestine channel) syndrome; eversion of the lips indicates the terminal stage of a Taiyin (Spleen/Lung channel) syndrome; dry and scorched lips indicate pathology in the flesh; withered lips indicate pathology in the Spleen; sores on the lips indicate the resolution of pathogens from the exterior; cracked lips indicate the emergence of toxins from within; sores inside the lips indicate intestinal parasites; fragmentation of the upper lip indicates heat in the Stomach meridian; deviation of the mouth corner indicates wind striking the sinews of the Yangming meridian; puckering of the lips indicates wind entering the vessels of the Yangming meridian. Manifestations that are excessive indicate pathology in the exterior; manifestations that are deficient indicate pathology in the interior. These are all variations in morphology. Observing morphology while viewing complexion: reddish lips represent the normal color; deep red indicates excess; pale red indicates deficiency; pale white with blackish tones indicates severe cold; deep red with dullness indicates profound heat; deep blue indicates pain; pale blue indicates cold. White lips indicate Spleen deficiency; yellow lips indicate Spleen disease. Light colors indicate deficiency of healthy Qi; dark colors indicate excess of pathogenic Qi. Bright, lustrous, and blood-colored complexions indicate life; withered, dull, and bloodless complexions indicate death. These are all differences in complexion. Discussing morphology and complexion separately serves to identify the normal state; observing them together serves to understand variations. However, investigating the normal and the variable, and tracing the beginning and end, although their substance and function differ, none do not take Shen (Spirit/Vitality) as the foundation. What is called Shen is brightness, lucidity, and the presence of blood color. Possession of Shen leads to life; loss of Shen leads to death. The *Yi Zhuan* (Commentary on the Book of Changes) states: "Essence and Qi condense to form things; wandering souls undergo transformation; thus, one can know the conditions of spirits and ghosts." This refers to the distinction between life and death.