Chen Mai (沉脉) is contrasted with Fu Mai (浮脉), and its definition in textbooks states: “light pressure yields no response, heavy pressure begins to yield, lifting shows insufficient pressure while pressing shows excess.” Regarding pulse diagnosis (脉诊), especially the sensations beneath the fingers, it is indeed challenging to describe in words. However, some definitions and conceptual ideas can be misleading when written this way, right? What does “heavy pressure begins to yield” mean? How heavy should the pressure be, and where should it be applied? To the flesh, to the tendons, to the bones, or beneath the bones? What level of pressure qualifies as heavy? Ah, some things in textbooks just don’t hold up under scrutiny. Upon closer examination, it becomes unclear which definition is correct.
So, what exactly constitutes Chen Mai? There should be some explanation, right?
In my understanding, the human body can be divided into layers: skin, fat, muscle, tendons, and bones, which correspond to the five organs: Lung (肺), Heart (心), Spleen (脾), Liver (肝), and Kidney (肾). The muscle layer corresponds to the Spleen layer; if the pulse is above or on the muscle, it can be considered Fu Mai (浮脉); if the pulse is beneath the muscle and above the tendons, it is Chen Mai (沉脉). If the pulse can only be felt at the tendon and bone level, it is called Fu Mai (伏脉). Therefore, the definition of “heavy pressure begins to yield” is incorrect; heavy pressure should reach the bone? That would be Fu Mai, which is even deeper than Chen Mai.
Now, let’s explore why the pulse may be deep. I believe there are several reasons:
1. Qi (气) is internal. It is said that Chen Mai indicates internal Qi, meaning the pulse’s dynamic state is at this internal level. However, simply being internal does not specify what the problem is, as some healthy individuals may also exhibit Chen Mai.
2. Qi is obstructed. This indicates that some pathogenic factors hinder the outward flow of Qi, causing it to be trapped internally, such as water retention, phlegm, or blood stasis.
3. Qi deficiency cannot express outward. Due to a weak constitution, Qi deficiency, or Yang deficiency, the Qi lacks the strength to reach the surface. If a person is weak, their pulse is typically Chen, and even if they contract an external pathogen, their pulse will not become Fu.
Chen Mai indicates disease:
A strong Chen pulse indicates internal excess, while a weak Chen pulse indicates internal deficiency. Chen indicates internal conditions, but it is essential to observe the accompanying pulse characteristics; sometimes, it is necessary to consider multiple accompanying pulses to determine the issue. For example, a Chen pulse that is rapid is often thought to indicate internal heat. However, a rapid Chen pulse does not necessarily mean internal heat; it must also be assessed for strength or weakness to clarify the situation. If the rapid Chen pulse is strong, it suggests internal heat; if it is weak, it may not indicate true heat but rather a deficiency of heart Yang, leading to weak pulsations and compensatory increased heart rate, which Western medicine refers to as compensatory tachycardia. Although Chen Mai primarily indicates internal conditions, it is associated with Yin; there can be cases of Yang deficiency with excess Yin, Yang stagnation internally, or extreme heat resembling Yin. The differentiation must be made between strength and weakness. If Yang Qi is weak, excess Yin generates cold, resulting in a slow and weak pulse; prolonged pressure reveals a small, weak pulse, indicating deficiency, cold, or counterflow. If Yang Qi is stagnant, the pulse is deep, and if it is strong and unyielding, it indicates excess, water retention, or stasis.
Below is a poem summarizing the diseases associated with Chen Mai:
Poem on Main Diseases:
Deep pulse indicates water retention and Yin diseases,
Rapid heat, slow cold, and phlegm present.
Weak and deep indicates deficiency and Qi,
Deep and strong indicates accumulation and cold.
Deep pulse at the cun indicates phlegm and water retention in the chest,
Deep pulse at the guan indicates internal cold pain and obstruction.
Deep pulse at the chi indicates turbidity and diarrhea,
Kidney deficiency affects the lower back and lower source.
(Chen Mai indicates internal conditions; a strong pulse indicates internal excess, while a weak pulse indicates internal deficiency. Chen indicates Qi and also indicates water retention, deep and slow indicates cold, deep and rapid indicates internal heat, deep and slippery indicates phlegm and food retention, deep and choppy indicates Qi stagnation, deep and weak indicates cold and heat, deep and slow indicates cold and dampness, deep and tight indicates cold pain, deep and firm indicates cold accumulation.)
——Excerpt from “Binhai Pulse Studies”