凡诊三部。浮沉脉不见。即当以神气形色相参。委曲求之如形色神气不备。脉则若有若无而未脱。此为邪气伏藏。
若形色神气已备。此乃天真绝矣。
经云。诸浮脉无根者。皆死。是有表无里。谓之孤阳。造化所以亘古不息者。一阴一阳。互为其根。阴既绝矣。阳
岂独存乎。人身之气血亦然。
外入之病。左脉大于右寸。脉盛于尺常也。然风寒暑湿则然。如劳役饮食跌扑虽为外入。亦属内伤。故右手气口。
大于人迎。劳役伤者。两寸俱虚。饮食伤者。右关微盛。跌扑伤者。气血皆滞。脉弦涩滑。伤左左不和。伤右右不
和。内出之病。如喜怒忧思悲恐惊。则右脉大于左荣气病。脉弦小而数。卫气病。脉滑大而数。荣病尺盛于寸。卫病寸
盛于尺。又外入之病。见阳脉为易治。内出之病。见阴脉为可治。反者不救。
脉浮病在表。脉沉病在里。此表里之纲领。亦有见表症。其脉不浮。见于肌肉之间。按之不足。轻举有余。如波涌
之状。泛上而急。亦表也。有见里症。其脉不沉。见于肌肉之间。举之不足。按之有余。如漫流之水。沉静不急。亦里
也。又寸盛亦主表。尺盛亦主里。如此方尽表里之义。
辨寒热以迟数二脉为本。此一定之法。如热症见数脉。按之不鼓。觉滑利而虚。乃虚火游行于外。非真热乃假热。
当作元气不足治。若诊而实。方为真热。寒症见迟脉。诊之鼓击。涩滞而实。是实火伏匿于内。非真寒。乃假寒。当作
邪气有余治。若诊而寒。方为真寒。真假不差。投药方效。
Whenever palpating the three positions (Cun, Guan, Chi), if neither the floating (Fu) nor the deep (Chen) pulse is distinctly perceived, one must correlate this with the patient's spirit (Shen), complexion, and physical form, seeking the truth through careful deduction. If the spirit, complexion, and form are incomplete, yet the pulse still exists in a faint, intermittent manner without being completely absent, this indicates that pathogenic factors are latent and hidden within the body.
If the spirit, complexion, and form appear complete (indicating a collapse of essence before death or extreme depletion), this signifies the exhaustion of primordial true Qi (Yuan Qi).
The Classics state: "All floating pulses lacking a root indicate death." This represents having exterior manifestations without interior support, termed "Lone Yang" (Gu Yang). The reason nature remains perpetual is that Yin and Yang serve as roots for each other. If Yin has been exhausted, how can Yang exist alone? The same applies to Qi and Blood in the human body.
For diseases entering from the exterior, it is customary for the left pulse to be larger than the right Cun position, and for the pulse to be vigorous at the Chi position. This holds true for Wind, Cold, Summer-heat, and Dampness. However, injuries from overexertion, improper diet, or falls/blows, although seemingly caused by external factors, also belong to internal injury categories. Therefore, the Qi Kou pulse on the right hand is larger than the Ying Sheng pulse. In cases of overexertion injury, both Cun positions are deficient. In cases of dietary injury, the right Guan position is slightly excessive. In cases of traumatic injury, Qi and Blood stagnate, resulting in a Wiry (Xian), Choppy (Se), or Slippery (Hua) pulse. Injury to the left side causes disharmony in the left pulse; injury to the right side causes disharmony in the right pulse.
For diseases arising from within, such as those caused by emotions like joy, anger, worry, thought, grief, fear, or shock, the right pulse becomes larger than the left. If Ying (Nutrient) Qi is diseased, the pulse is Wiry, small, and rapid. If Wei (Defensive) Qi is diseased, the pulse is Slippery, large, and rapid. In Ying Qi disease, the Chi pulse is vigorous relative to the Cun pulse; in Wei Qi disease, the Cun pulse is vigorous relative to the Chi pulse. Furthermore, for exterior diseases, the appearance of Yang pulses indicates ease of treatment; for interior diseases, the appearance of Yin pulses indicates treatability. If the presentation is reversed (Yang pulses in interior disease, Yin pulses in exterior disease), it is incurable.
A floating pulse indicates disease in the Exterior (Biao); a deep pulse indicates disease in the Interior (Li). This is the general principle for distinguishing Exterior and Interior. However, there are cases where Exterior symptoms are present, but the pulse does not float: the pulse is felt between the muscles, feels insufficient upon heavy pressure, and sufficient upon light lifting, resembling surging waves—rising quickly and urgently. This also belongs to the Exterior. There are also cases where Interior symptoms are present, but the pulse does not sink: the pulse is felt between the muscles, feels insufficient upon light lifting, and sufficient upon heavy pressure, resembling slowly flowing water—calm and not urgent. This also belongs to the Interior. Additionally, an excess in the Cun position primarily indicates Exterior conditions, while an excess in the Chi position primarily indicates Interior conditions. Only in this way is the meaning of Exterior and Interior fully understood.
Distinguishing Cold and Heat relies fundamentally on the Slow (Chi) and Rapid (Shu) pulses, which is a fixed method. If a Heat syndrome presents with a Rapid pulse, but upon pressing, the pulse does not beat vigorously, feeling slippery and empty, this indicates Deficient Fire wandering externally. It is not True Heat but False Heat, and should be treated as Yuan Qi deficiency. If the pulse feels solid and forceful upon examination, it is True Heat. If a Cold syndrome presents with a Slow pulse, but upon examination, the pulse beats vigorously, feeling choppy and solid, this indicates Excess Fire hiding internally. It is not True Cold but False Cold, and should be treated as Pathogenic Excess. If the pulse feels cold and weak upon examination, it is True Cold. Only when the distinction between True and False is accurate will the medication be effective.