3. Sanjiao Differentiation

3. Sanjiao Differentiation

This approach divides exogenous febrile diseases into three categories—upper jiao, middle jiao, and lower jiao—based on the site of onset and the severity of the condition.

(1) Upper Jiao Syndrome

① Hand Taiyin Lung Syndrome: Headache, fever, chills (more heat than cold), spontaneous sweating, thirst, cough, and a floating, rapid pulse or a particularly prominent pulse at the cun position—indicating the need to release the exterior and disperse lung qi. The representative formulas are Sangju Yin and Yinqiao San. ② Hand Jueyin Pericardium Syndrome: A dark-red tongue, confusion, delirium, or tongue stiffness and limb paralysis—indicating the need to clear the heart and open the orifices. The representative formulas are Angong Niuhuang Wan and Zixue Dan (both from the "Differentiation of Warm Diseases").

(2) Middle Jiao Syndrome

① Foot Yangming Stomach Syndrome: Fever, thirst, and a large pulse—indicating the need to purge fire and save yin. The representative formula is Baihu Tang or Ren Shen Baihu Tang. ② Foot Taiyin Spleen Syndrome: Feeling heavy as if wrapped in something, body heat not rising, severe body pain, chest tightness and nausea, greasy tongue coating and sluggish pulse—indicating the need to clear heat and transform dampness. The representative formulas are Sanren Tang (from the "Differentiation of Warm Diseases") and Dai Pu Xia Ling Tang (also from the "Differentiation of Warm Diseases").

(3) Lower Jiao Syndrome

① Foot Shaoyin Kidney Syndrome: Body heat and flushed face, hands and soles of feet warmer than the backs of the hands, irritability and insomnia, chapped lips and dry mouth—indicating the need to nourish yin and blood. The representative formulas are Zhibo Dihuang Tang (from the "Medical Classic of the Golden Mirror") and Qiju Dihuang Tang. ② Foot Jueyin Liver Syndrome: Deep-seated heat, a vague, restless feeling in the heart, trembling of the hands and feet, sometimes even convulsions—indicating the need to nourish the liver and calm the wind. The representative formulas are Da Ding Feng Zhu and San Jia Fu Mai Tang (both from the "Differentiation of Warm Diseases").

Sanjiao differentiation was created by the warm disease master Wu Jutong. The upper jiao syndrome is equivalent to the Taiyang syndrome in the Six Meridians and the Wei phase in the Wei-Qi-Ying-Xue differentiation, but with the addition of symptoms such as confusion, tongue stiffness, and limb paralysis caused by heat invading the pericardium, fully reflecting the characteristic of infectious diseases (especially severe acute infectious diseases) where heat can rapidly spread to the pericardium. The middle jiao syndrome is equivalent to the Yangming syndrome in the Six Meridians and the Qi phase in the Wei-Qi-Ying-Xue differentiation, but with the addition of damp-heat syndrome in the middle jiao caused by the combination of dampness and heat in the spleen, thus supplementing the deficiencies of the Six Meridians and the Wei-Qi-Ying-Xue differentiation and appropriately reflecting the clinical characteristics of gastrointestinal infectious diseases such as typhoid fever and chronic dysentery. The lower jiao syndrome is equivalent to the Ying phase and Xue phase in the Wei-Qi-Ying-Xue differentiation, while also possessing some characteristics of the Jueyin syndrome in the Six Meridians.

IV. Etiological Differentiation

Traditional Chinese Medicine's understanding of etiology originates from texts such as the "Inner Canon," "Synopsis of the Golden Cabinet," and "Three Causes Formula," broadly categorizing pathogenic factors into three types: external causes, internal causes, and neither internal nor external causes. Internal causes are also known as the "Seven Emotions," external causes are known as the "Six Evils," and neither internal nor external causes refer to injuries caused by diet, overwork, sexual activity, animals, or sharp objects. In modern times, some scholars have summarized these factors into just two categories: internal and external.