1. Heat Exuberance
“When after guì zhī tāng is taken and following major sweating there is major vexation and thirst, and the disease is unresolved and the pulse is surging and large, bái hǔ jiā rén shēn tāng (White Tiger plus Ginseng Decoction) governs”.
“In cold damage if vomiting or purgation (methods) are used, and after seven or eight days the condition has not resolved, heat is bound in the interior, (and there is) heat in both the exterior and interior, (with) frequent aversion to wind, great thirst, a dry tongue, vexation, and a desire to drink several shēng of water, bái hǔ jiā rén shēn tāng (White Tiger plus Ginseng Decoction) governs”.
“In cold damage when the pulse is floating, and there is heat effusion with an absence of sweating, the exterior has not yet resolved; bái hǔ tāng (White Tiger Decoction) can not be given. If there is thirst with a desire to drink and no exterior signs, bái hǔ jiā rén shēn tāng (White Tiger plus Ginseng Decoction) governs”.
“In cold damage when great heat effusion is absent and there is a dry mouth, thirst, heart vexation, and slight aversion to cold in the back, bái hǔ jiā rén shēn tāng (White Tiger plus Ginseng Decoction) governs”.
“If there is thirst with a desire to drink water, a dry mouth, and dry tongue, then bái hǔ jiā rén shēn tāng (White Tiger plus Ginseng Decoction) governs”.
“When there is diarrhea with a desire to drink water, this indicates heat and bái tóu wēng tāng (Pulsatilla Decotion) governs”.
The Shāng Hán Sù Yuán Jí (Discourse on Tracing back to the Source of (the Discussion) of Cold Damage) says: “the presence or absence of thirst is the main determining factor of the existence of heat. When there is no heat in the interior, there will be no thirst, and if thirst is present, (due to) a lack of fire in the lower burner, fluids are unable to be steamed by the bladder resulting in a lack of moisture (fluids) in the mouth. Although thirst is present, there will be a lack of desire and an inability to drink copious amounts of water. If the stomach is hot and dry, it would be completely logical that there would be thirst with a desire to drink, as opposed to an absence of heat in the interior still with a desire to drink fluids”. In the Jué Yīn chapter in the Shāng hán lùn, major heat has caused excessive loss of water, and this lack of water will result in thirst. All of the patterns in the lines above are the result of great heat, which has damaged fluids; therefore they all use bái hǔ jiā rén shēn tāng. Bái tóu wēng tāng is also used to clear superabundant heat.
2. Water Amassment
“…………If the pulse is floating, urination is inhibited, and there is slight heat with dispersion thirst, wǔ líng sǎn (Five-Ingredient Powder with Poria) governs”.
“In wind strike when there is heat effusion that is unresolved for six or seven days and vexation; (here) there is an exterior and interior pattern with thirst with a desire to drink water and vomiting immediately after ingesting fluids, this is called water counterflow, and wǔ líng sǎn (Five-Ingredient Powder with Poria) governs”.
“When sweat has already been promoted and the pulse is floating and rapid, and there is vexation and thirst, wǔ líng sǎn (Five-Ingredient Powder with Poria) governs”.
“In Tài Yáng disease……when there is thirst with a desire to drink water, give a small amount of water, for only by this method will the condition be eliminated. If there is thirst, wǔ líng sǎn (Five-Ingredient Powder with Poria) is suitable”.
A wǔ líng sǎn (Five-Ingredient Powder with Poria) pattern is primarily the result of obstruction in urinary function manifesting with inhibited urination. There is accumulation and fullness of water toxicity in the blood, and the gastro-intestinal tract is unable to reabsorb water into the blood. Water amassment has also now been generated within the stomach resulting in this kind of obstruction to the body’s fluid metabolism and there is a failure to secrete fluids in the salivary glands and the mucus membranes in the mouth resulting in thirst. Therefore, we know that a lack of water or water amassment can both lead to thirst, so with a lack of water, one needs to merely supplement and fill the water aspect with a formula like bái hǔ jiā rén shēn tāng, where on the hand it clears heat, while on the other, it also generates fluids. With water amassment, treatment involves disinhibiting water, and while wǔ líng sǎn can stop thirst, it primarily eliminates amassed water. This thirst is similar to that associated with zhū líng tāng (lines 223 and 319), however the pathological changes with this formula (WLS) are in the bladder.
3. Damage to Yīn
“In Shào Yīn disease when there is a desire but inability to vomit, heart vexation, a desire only to sleep, and after five or six days there is spontaneous diarrhea and thirst, this belongs to Shào Yīn. (Because there is) vacuity, water intake should relieve (the thirst)”.
“In Jué Yīn disease, when there is thirst with a desire to drink water, give a small amount of water and there will be recovery”.
“In Jué Yīn disease there is dispersion thirst, qì surging upwards into the heart, pain and heat in the heart, hunger with no desire to eat, and vomiting of roundworms after eating. If purgation is used, this will result in incessant diarrhea”.
The Shāng Hán Míng Lǐ Lùn (The Clear Rationale of Cold Damage) says: “When pathogenic qì first enters the interior, warm qì is scattered and is unable to be absorbed becoming heat. This heat is fumed and steamed, which burns the diaphragm resulting in contention and the inevitable consumption of fluids, which gradually creates thirst. Although the patient is thirsty and has a desire to drink water, they are unable to drink copious amounts. If large amounts of water are drunk, the heat would still not be dispersed, and this would result in rheum stoppage disease”. All yīn patterns with thirst are typically not due to repletion heat, but are the result of the exhaustion of fluids and the harassment of vacuous yáng. Therefore, cool and cold (medicinals) should not be carelessly administered, nor should copious amounts of water be given. All three lines above are patterns due to yīn damage and vacuous fire harassing the upper, therefore Wèi Lì-Tóng recommends giving fù zǐ tāng (Aconite Decoction) in line 282 to warm Shào Yīn.
 A text written in 1707 by Qián Huáng (錢潢)
 Wèi Lì-Tóng said: “What is the interior pattern? It manifests with vexation, thirst with a desire to drink, and vomiting immediately after ingesting fluids. What is the exterior pattern? It manifests with a headache, tightness of the nape, and aversion to cold, heat effusion, and sweating”.
 A Jīn dynasty text written by Chéng Wú-Jǐ (成无己)