络有阴阳，阴络在内，深而难见。阳络在外，滑而易见。其色随四时推迁而变，遂即所变之色，以诊
寒热。寒多则脉凝泣，凝泣则色青黑。热多则脉淖泽，淖泽则色黄赤。
胃之大络，名曰虚里，贯膈络肺，出于左乳之下，其动应衣，以候宗气。若动之微而不见，则为不及，
主宗气内虚。若动之应衣而甚，则为太过，主宗气外泄。若三四至一止，或五六至一止，主有积聚。若绝
不至，则死矣。
脐之上，主候胃。脐之下，主候肠。其扪上下之腹皮寒热，则知胃肠有寒热之病。胃中有热，每喜冷冻饮料
。肠中有寒，多喜热汤。然与之饮热，不可过热，与之饮寒，不可过寒，惟当适其寒温之宜而已。
胃中有热，上发口糜，心空善饥。肠中有热，下泻热物，色黄如粥。胃中有寒，面清冷而厥，腹胀而疼
。肠中有寒，小便尿白，飧泻肠鸣。
形分强弱，强者外邪难犯，弱者外邪易干。食多而肥者，强也。若食少而肥者，非强也，乃痰也。
肥人最怕脉如绵絮，谓之无气，则主死矣。食少而瘦者，弱也，若食多而瘦者，非弱也，乃火也。瘦人最怕
肉干着骨，谓之消瘦，亦主死矣。
《经》曰∶形气已脱。九候虽调，获死者，谓形脱无以贮气也。形气俱虚，寸口脉调，可医者，谓形气
未相失也。形盛而肥，脉小少气者，谓气不能胜形，形衰而瘦，脉大多气者，谓形不能胜气，均主死也。
络脉分为阴络和阳络。阴络位于体内，位置深而难以看见；阳络位于体表，滑利且容易看见。络脉的颜色会随着四季的更替而变化，因此可以根据颜色的变化来诊断寒热病证。寒气偏盛时，脉道凝滞不畅，颜色呈现青黑色；热气偏盛时，脉道滑润泽亮，颜色呈现黄赤色。
胃的大络脉，名为虚里，贯穿膈肌联络肺脏，出于左侧乳下部位，其搏动可以透见衣被，通过观察此处搏动来候察宗气（积聚于胸中的大气）。如果搏动微弱而看不见，属于不及，主宗气内虚；如果搏动剧烈透见衣被，属于太过，主宗气外泄。如果脉搏跳动三四次出现一次停顿，或者五六次出现一次停顿，主体内有积聚之邪。如果脉搏完全停止不跳，则预示死亡。
肚脐上方，主要候察胃的状况；肚脐下方，主要候察肠的状况。触摸上下腹部的皮肤寒热，就能知道胃肠是否有寒热病变。胃中有热，患者通常喜欢喝冷冻饮料；肠中有寒，患者通常喜欢喝热汤。但是给患者饮用热饮时，不可过热；给患者饮用冷饮时，不可过冷，只应当适宜其寒温的需求即可。
胃中有热，火热上攻会导致口腔糜烂，心中空虚且容易饥饿；肠中有热，向下排泄热性糟粕，粪便颜色黄如粥状。胃中有寒，面色清冷且四肢厥逆，腹部胀满疼痛；肠中有寒，小便清白，大便完谷不化且肠鸣。
形体分为强和弱两种。形体强者，外邪难以侵犯；形体弱者，外邪容易干扰。吃得很多而且肥胖的人，属于形体强。如果吃得很少却肥胖的人，并非形体强，而是痰湿内盛所致。肥胖的人最怕脉象像绵絮一样软弱无力，这叫做“无气”，主死证。吃得很少而且消瘦的人，属于形体弱。如果吃得很多却消瘦的人，并非形体弱，而是火邪亢盛所致。瘦人最怕肌肉干枯紧贴骨头，这叫做“消瘦”，也主死证。
《内经》说：如果形体衰败脱失，即使九候脉象调和，也会死亡，这是因为形体脱失无法容纳和贮藏气的缘故。如果形气和脉气都虚弱，但寸口脉象调和，是可以治愈的，这是因为形气尚未相互背离。形体壮盛肥胖，但脉象细小且少气的人，是气不能胜任形体，主死；形体衰弱消瘦，但脉象盛大且多气的人，是形体不能胜任气，也主死。
Luo vessels (Collaterals) are divided into Yin Luo and Yang Luo. Yin Luo is located internally, deep and difficult to see; Yang Luo is located externally on the surface, smooth and easy to see. The color of the Luo vessels changes with the progression of the four seasons; therefore, cold or heat patterns can be diagnosed based on these color changes. When cold predominates, the vessels become stagnant and sluggish, resulting in a bluish-black color. When heat predominates, the vessels become moist and glossy, resulting in a yellowish-red color.
The major Luo vessel of the Stomach is named Xuli (虚里), which penetrates the diaphragm, connects with the Lung, and emerges below the left breast. Its pulsation can be seen through clothing, allowing for the assessment of Zong Qi (Gathering Qi). If the pulsation is faint and invisible, it indicates insufficiency, signifying internal deficiency of Zong Qi. If the pulsation is vigorous and visible through clothing, it indicates excess, signifying leakage of Zong Qi externally. If the pulse beats three or four times before a pause, or five or six times before a pause, it indicates the presence of accumulations (masses). If the pulse ceases completely, death ensues.
The area above the umbilicus primarily reflects the condition of the Stomach; the area below the umbilicus primarily reflects the condition of the Intestines. By palpating the temperature of the abdominal skin above and below, one can determine whether there is cold or heat pathology in the Stomach and Intestines. Heat in the Stomach often leads to a preference for cold drinks. Cold in the Intestines often leads to a preference for hot soups. However, when providing hot drinks, they should not be excessively hot; when providing cold drinks, they should not be excessively cold. One should only provide what is appropriate for their tolerance of cold and heat.
Heat in the Stomach may manifest upward as oral ulcers (mouth sores) and a sensation of emptiness in the heart with frequent hunger. Heat in the Intestines may manifest downward as the discharge of hot fecal matter, yellow in color like porridge. Cold in the Stomach manifests as a clear and cold complexion with cold extremities, abdominal distension, and pain. Cold in the Intestines manifests as clear white urine, undigested stool in diarrhea (Sun-xie), and borborygmus (intestinal rumbling).
Physical constitution is divided into strong and weak. Those who are strong are resistant to invasion by external pathogens; those who are weak are easily affected by external pathogens. Individuals who eat much and are fat are considered strong. However, individuals who eat little but are fat are not strong; rather, this is due to Phlegm accumulation. Fat individuals most fear a pulse that feels soft and cotton-like, termed "Qi-less," which indicates death. Individuals who eat little and are thin are considered weak. However, individuals who eat much but are thin are not weak; rather, this is due to Fire pathogen. Thin individuals most fear muscles that are dry and cling tightly to the bones, termed "emaciation," which also indicates death.
The Classics state: If physical form has degenerated and departed, even if the nine pulses are harmonious, death occurs because the degenerated form cannot store Qi. If both physical form and Qi are deficient, but the Cun-kou (Radial) pulse is harmonious, recovery is possible because form and Qi have not yet separated. If the body is robust and fat, but the pulse is small and Qi is scant, it means Qi cannot overcome the Form, indicating death. If the body is frail and thin, but the pulse is large and Qi is abundant, it means Form cannot overcome Qi, also indicating death.