In TCM, Morning Fasting Pulse-Taking Is the Ideal

People often ask me why I require patients to come in the morning or forenoon on an empty stomach. Everyone is full of doubt about this point, which stems from a lack of understanding of TCM diagnostics, especially pulse diagnosis.

In the Maiyao Jingwei Lun chapter of the Huangdi Neijing (Yellow Emperor's Inner Canon), a basic principle of TCM diagnosis was already established: taking the pulse at dawn on an empty stomach is the way to most truthfully diagnose the patient's condition.

The Maiyao Jingwei Lun has this passage:

"Huangdi asked: What of the diagnostic method? Qibo answered: The diagnostic method is normally carried out at dawn (pingshen), when yin qi has not yet stirred, yang qi has not yet dispersed, food and drink have not yet been taken, the channel-qi is not yet exuberant, the collateral-qi is harmonized, and qi and blood are not yet disordered; thus one can diagnose the abnormal (over-stepping) pulse. Feel the movement and stillness of the pulse, inspect the essence-spirit of the eyes, observe the five colors, examine the excess and deficiency of the five zang and the strength and weakness of the six fu, and the flourishing and declining of the form. Combining these methods, one determines the division between life and death."

The meaning is this: Huangdi asks Qibo how the pulse is taken. Qibo answers that pulse-taking should be done in the morning on an empty stomach, because morning is the time when yin and yang hand over: yin qi has not yet been stirred, yang qi has not yet been dissipated, food has not been eaten, the channel-qi is not exuberant, the collateral-qi is harmonized, and qi and blood are not yet disordered. Under these conditions it is easy to diagnose the pathologic pulse.

Moreover, while taking the pulse, on the one hand one examines the movements of the pulse, and on the other hand one should note the patient's spirit in the face and eyes, observe the manifestations of the five colors, judge the excess and deficiency of the five zang and the strength and weakness of the six fu, and the flourishing and declining of the body. Combining these methods, one determines the patient's life and death.

In modern hospitals, many tests require fasting, and in most Grade-A tertiary hospitals some tests are not done after the forenoon, because the body's indicators differ before and after a meal.

In fact, as early as several thousand years ago, TCM had already recognized this regularity and therefore set such a diagnostic standard.

It is just a pity that nowadays, not only the general public but even the TCM doctors in hospitals are few who strictly follow this standard.

Personally, except that I occasionally accommodate patients who are pressed for time by taking the pulse in the afternoon, I schedule most patients for the morning or before 10:30 in the forenoon, never later than 11 o'clock. Sometimes when there are many patients, I start working as early as six in the morning.

Even for patients whose pulses I take in the afternoon, I instruct them to fast for several hours; although the result is still not as good as morning fasting pulse-taking, it is better than coming right after a full meal.

In addition, on the day of pulse-taking, before the pulse is taken, one should not take any Chinese or Western medicine, unless the patient has a special life-threatening condition. After taking medicine, the patient's pulse also changes markedly; for example, a hypertensive patient whose pulse was wiry may no longer have a wiry pulse after taking antihypertensive medicine, affecting the diagnosis. Patients must pay attention to all this.