Library

The *Neijing* (Inner Canon), in the chapter "Yin Yang Bie Lun" (Differentiation of Yin and Yang), states: "When the Two Yang (Yangming meridians) are knotted, it is called Xiao (Wasting-Thirst)." In the chapter "Mai Yao Jing Wei Lun" (Essentials of Pulse Diagnosis), it states: "Dan-heat (febrile heat) develops into Xiao Zhong (Middle Wasting-Thirst characterized by polyphagia)."

According to Li Dongyuan: The "Two Yang" refers to the Yangming meridians. The Hand-Yangming Large Intestine meridian governs body fluids; when afflicted with Xiao, symptoms such as yellow eyes and dry mouth appear, indicating a deficiency of fluids. The Foot-Yangming Stomach meridian governs blood; latent fire within the blood leads to efficient digestion and easy hunger, indicating a deficiency of blood. The term "knot" (Jie) refers to insufficient fluids that fail to moisten due to stagnation; this is a disease caused by dryness and heat. This arises from long-term consumption of sweet, delicious, and fatty foods, causing Qi to overflow upward and transform into Xiao Ke (Wasting-Thirst). Treatment should employ Lancao (Pei Lan, *Herba Agrimoniae* or *Eupatorii Herba*) to eliminate stale Qi. One must not consume Gao Liang (rich food) or Fang Cao (aromatic herbs) and Shi Yao (mineral drugs), as their pungent and fierce nature will assist dryness and heat.

The *Suwen*, in the chapter "Tiao Jing Lun" (Regulating the Meridians), states: "If Heart heat transfers to the Lung, it transmits as Ge Xiao (Upper Wasting-Thirst/Intersticial Thirst)." Generally, treating Xiao, Dan, Pu Ji (collapse/stroke), Pian Ku (hemiplegia), Wei Jue (flaccidity/cold limbs), and Qi Man Fa Ni (distension and rebellious Qi) often involves wealthy individuals; these are diseases resulting from rich diets.

Qibo states: "If the pulse is substantial, even after a long duration, the disease is treatable; if the pulse is wiry and small, after a long duration, it is untreatable." Later, Xiao was divided into Three Xiaos: Shang Xiao (Upper Xiao) presents with red cracks on the tongue and extreme thirst with desire to drink.

The *Mai Jing* (Pulse Classic) states: "When Jin (tight) and Shu (rapid) pulses contend, it becomes Xiao Ke." A soft and scattered pulse indicates one should suffer from Xiao Ke.

The *Bing Ji* (Pathogenesis) discusses Xiao Ke as a disease of the San Jiao (Triple Burner): The ailment of Xiao Ke affects the San Jiao. Shang Xiao belongs to the Lung; symptoms include drinking much water but eating little, normal stools, and clear urine, indicating dryness in the Upper Jiao. Treatment should utilize damp-draining methods to moisten dryness. Zhong Xiao belongs to the Stomach; symptoms include thirst, large food intake, and dark yellow urine, with heat capable of digesting food, indicating heat in the Middle Jiao. Treatment should employ purgative methods. Xia Xiao (Xiao Shen/Lower Xiao) initially manifests as Gao Lin (Chyluria/Greasy Strangury), where urine resembles oil paste. When the disease matures, the complexion becomes dark, the body emaciates, ears become dry and black, and urine is turbid with lipid fluid. The treatment method should nourish Blood to separate the clear from the turbid, allowing self-healing.

Chen Wuyue states: Xiao Ke belongs to the Heart; thus, vexation causes Heart Fire to scatter and immerse, leading to thirst and desire to drink. All pulses being soft and scattered indicate Excess of Qi and Deficiency of Blood. Zhong Xiao belongs to the Spleen; after Dan-heat subsides, it becomes Zhong Xiao. Zhong Xiao has three subtypes: one due to Han Zhong (Cold striking the middle), where Yin excess and Yang depression eventually generate Re Zhong (Heat in the middle). The classic states: "A Hong Da (surging-large) pulse, with Yin deficiency and Yang excess, is Re Zhong." Polyphagia and frequent urination constitute Zhong Xiao. If Yin pathogen is rampant and essence leaks without interaction, it becomes Qiang Zhong (Priapism/Excessive Sexual Potency). Reaching Qiang Zhong is indeed perilous. Xiao Shen belongs to the Kidney. During times of robust health, if one is not cautious and indulges in sexual activity, leading to Kidney decline in old age, and additionally consumes mineral drugs, losing true Qi, symptoms include dry mouth, spontaneous seminal emission, and frequent urination without thirst. The classic states: "When the Kidney is Excess, there is Xiao; without thirst but with spontaneous urination, it is named Xiao Shen, also called Nei Xiao (Internal Wasting-Thirst)."