Library

Human beings rely on water and grain (diet) as their foundation; therefore, if water and grain are cut off, death ensues. Zhang Zhongjing stated: "When water enters the meridians, blood is formed; when grain enters the stomach, the vessel pathways begin to circulate." The fierce and rapid qi derived from water and grain becomes Wei Qi (defensive qi that circulates outside the vessels), while the refined and gentle essence becomes Ying Qi (nutritive qi that circulates inside the vessels). If water metabolism fails, Ying Qi scatters; if grain digestion ceases, Wei Qi perishes. Therefore, in variola (smallpox), if a patient can eat, even severe cases are auspicious; if they cannot eat, even mild cases are ominous. However, there are cases where those who can eat die, and those who cannot eat survive. Why? Generally, those unable to eat may have internal excess in the zang-fu organs with constipation, relying on residual food qi for nourishment; after the pustules mature, they will naturally be able to digest food and desire eating. Those who can eat are suffering from pathogenic heat accelerating digestion ("killing grain"). This corresponds to Wang Shuhe's statement: "Dry mouth desiring water intake, eating much yet feeling hungry and weak." Such individuals will soon develop complications. Only patients with exanthems (rash diseases) often cannot eat because of oral discomfort and lack of appetite; once the rash subsides, appetite returns. Moreover, since the disease course is short and there is no significant depletion of qi and blood during the pustule-filling stage, it causes no harm.

If the fever from smallpox or measles is mild, with calm breathing, peaceful spirit, and comfortable mind, this is a favorable sign. Conversely, if there is painful restlessness and incessant irritability, these are generally ominous signs, though they vary by location and timing. For instance, pain in the forehead and head: during the initial fever stage, it indicates fire attempting to ascend, and treatment should employ mild releasing-the-exterior methods; during the pustule-filling stage, swollen and puffy pustules are considered normal manifestations; during the crusting stage, it results from careless exposure to wind-cold or extreme deficiency of qi and blood causing floating fire to rush upward. Detailed differentiation and treatment are required. Pain in the throat: during the initial fever stage, it clearly belongs to fire. During the swelling stage, severe pain accompanied by coughing indicates dense pustules in the throat; during the crusting stage, it signifies aggregation of fire-toxin, requiring vigilance against asthma-like urgency as an adverse outcome. Pain in the skin: during the initial onset, it means toxin-fire desires to vent but the muscle layer is closed and tight; during the swelling and filling stage, it means toxin transforms into pus, which is also a normal manifestation; after scabs fall off, it indicates blood dryness failing to nourish the skin, compounded by external fire burning. Pain in the chest and abdomen: during the initial fever stage, it may result from dietary injury, latent smallpox toxin, or pre-existing conditions, requiring careful analysis and treatment. Pain in the waist and knees: during the initial fever stage, although kidney meridian disorders are difficult to treat, if the lips are not swollen, the mouth has no foul odor, macules are absent, and fever is not intense, this indicates kidney deficiency failing to expel toxins. In such cases, lifting and venting methods should be used to guide toxins outward; one must not prescribe recklessly, nor use overly cold medicines, lest the toxins become sunken and hidden, making them difficult to emerge. Pain in the four limbs may result from pediatric sprains or strains causing stagnant qi, trauma leading to blood stasis, or insufficient spleen yin failing to irrigate the limbs. These are the essential principles for diagnosing pain.