Zhang Jiebin elaborated on the true yin from five aspects.
The first is the image of true yin, that is, the appearance of true yin outside. Zhang Jiebin believes that yin is the essence, the yin is formed, and the external shape of the flesh, that is, born from the inner yin essence, is the image of the true yin.
The second is the dirt of the true yin, the so-called dirt of the true yin, that is, the internal organs where the true yin of the human body is located. The gate of life is the dirt of the true yin, the true yin is hidden in the body in the gate of life, the true yin is water, the basis of the fire of the gate of life, the fire of life is nourished in the yin water, and the true yin includes the yuan essence yuan qi in the gate of life.
The third is the use of true yin, which refers to the power and source of true yin nourishing the body, and adjusting the camp and guarding, and maintaining the physiological functions of the internal organs.
The fourth is the disease of true yin, which refers to the pathological manifestations of true yin deficiency. If the true yin is insufficient, there will be a fire decaying its essence, and the water will lose its source of the yang and yin deficiency.
Fifth, the treatment of true yin, the treatment of true yin diseases should supplement the life gate water and fire, with the right gui pill Gan Wen Yi fire to supplement the yang to match the yin, with the left gui pill pure gan zhuang water to supplement the yin to match the yang.