The text states that if the pulse does not reach fifty beats and then stops once, indicating that one organ lacks qi, which organ is it? The answer is: When a person inhales, the breath follows the yin inward; when exhaling, it follows the yang outward. Now, if the inhalation cannot reach the kidney but returns at the liver, it is known that the organ lacking qi is the kidney, as the kidney qi is exhausted first.

bubble_chart Note

1. Lingshu Chapter Five states: "A person cycles fifty times in one day and night, circulating the essence of the five organs. If it does not match this number, it is called reckless life. The so-called fifty cycles mean that all five organs receive qi, holding the pulse and counting its arrival. If the pulse does not skip once in fifty beats, all five organs receive qi. If it skips once in forty beats, one organ lacks qi. If it skips once in thirty beats, two organs lack qi. If it skips once in twenty beats, three organs lack qi. If it skips once in ten beats, four organs lack qi. If it does not reach ten beats and skips once, all five organs lack qi, indicating a short lifespan."
2. Note: Among the five organs, the kidney is the lowest, and the inhalation reaches it last. If the pulse does not reach fifty beats and stops once, it is known that the kidney has no support, and its qi is exhausted first. Exhaustion means it cannot follow the qi of the other organs upward.