2. Absorbing the "nutritive qi and blood" portion of the defensive qi, nutritive qi, and blood differentiation

2. Absorbing the "nutritive qi and blood" portion of the defensive qi, nutritive qi, and blood differentiation

Due to the prevailing conditions at the time, the Six Meridians of cold damage mainly employed pungent-warm exterior-releasing and emergency yang-restoring methods, while the diagnosis and treatment of issues such as yin deficiency, wind movement, blood rushing uncontrollably, and heat invading the pericardium were either insufficiently addressed or completely overlooked. Consequently, the application of "clearing heat and detoxifying," "nourishing yin and cooling blood," and "suppressing wind and opening the orifices" in formulation and medication was relatively limited. In this regard, the defensive qi, nutritive qi, and blood differentiation for warm diseases effectively fills these gaps, with the key being the nutritive qi and blood portions. In the defensive qi, nutritive qi, and blood differentiation, the defensive qi stage corresponds to exterior heat, while the qi stage corresponds to interior heat—both share significant similarities with the Sun and Yangming stages of the Six Meridians of cold damage. Only the nutritive qi and blood stage fully captures the characteristics of yin deficiency, blood rushing, wind movement, and heat invading the pericardium in febrile diseases. Therefore, in the "six-stage differentiation" for febrile diseases, the author incorporates the nutritive qi and blood portions of the defensive qi, nutritive qi, and blood differentiation, placing them sequentially after the Sun, Shaoyang, and Yangming stages, thus making them the fourth and fifth stages of febrile disease progression (see diagram).