外感邪未入里，则知味而食如常，入里则不思食矣。喜冷者，内热也。喜热者，
里寒也。得食稍安者，虚也。得食更甚者。实也。（虚人过食亦不安。）病由饮食而致者，
须问所伤何物。热者必渴，喜冷冻饮料，饮必多。若喜热饮，或冷冻饮料而不多，乃虚热，
非实热也。（火虚者，必不能饮冷。水虚者，虽火燥津干，然少得清润即止，以本虚，不能胜
水之冷气，故不能多饮也。）
大小便不禁，为肾败。（肾开窍于二阴，肾败则失其闭脏之职。）小便清白而长者，必非热
证。（亦有火在上焦者，导之使下则反黄矣。）黄赤而短者，热也。然劳倦生火，或思虑动火，或
泻利忘阴，或阴虚内热等证，小便多黄，虽亦为热，然是虚热，非实热也。津液由
于气化，气病则小便不利。气上脱者，必无小便。气闭者，亦无小便。小腹硬痛，
小便不利，为溺涩。利而大便黑，为蓄血。泻而腹满者，死。大便闭结，腹坚满，
痛不可按者，热结也。大便泻利为寒，然亦有热者，经所谓暴注属热也。（火性急速，
不及传化即出也。其势急迫，辟辟有声，如蟹沫然。若热随泻去，痛随利减，可不治。）又有
纯泻清水者，谓
之热结旁流。（内有燥矢。结成弹丸，挡住糟粕，止于其旁漏下清水也，必极臭。）皆热证也。
又大便鸭
溏者，为寒。色如霉酱，粘腻（不见糟粕颗粒也，为热所烁化之故。）极臭者，又为热。
When external pathogenic factors have not yet entered the interior, taste remains normal and eating habits are unchanged; once pathogens enter the interior, appetite is lost. Preference for cold drinks indicates internal heat (Neire). Preference for hot drinks indicates interior cold (Lihan). Symptoms that alleviate slightly after eating indicate deficiency (Xu). Symptoms that worsen after eating indicate excess (Shi). (Even in individuals with constitutionally deficient Qi, overeating can cause discomfort.) If the disease is caused by dietary indiscretion, one must ask what specific food was ingested improperly. Heat patterns invariably present with thirst, a preference for frozen beverages, and large volumes of intake. If one prefers hot drinks, or prefers cold drinks but consumes little, this is deficiency heat (Xure), not excess heat (Shire). (Those with Yang deficiency cannot tolerate cold drinks. Those with Yin deficiency may experience dryness due to fire scorching fluids, but drinking small amounts of cool, moistening liquids suffices because the root is deficiency, and the body cannot withstand the cold nature of water, hence they cannot drink much.)
Incontinence of both urine and feces indicates failure of the Kidney (Shen). (The Kidneys open into the two yin passages [anterior and posterior orifices]; when Kidney essence fails, it loses its function of securing the Zang organs.) Urine that is clear, white, and copious is definitely not a Heat pattern. (Note: There are cases where Fire resides in the Upper Jiao; if guided downward, the urine may turn yellow.) Urine that is yellow-red and scanty indicates Heat. However, exhaustion generating Fire, excessive worry stirring Fire, dysentery depleting Yin, or Internal Heat due to Yin Deficiency can all result in yellow urine. Although these represent Heat, they are Deficiency Heat (Xure), not Excess Heat (Shire). The generation and excretion of Body Fluids (Jinye) depend on Qi transformation (Qihua); Qi pathology leads to difficult urination. When Qi escapes upward, there will be no urine. When Qi is obstructed, there will also be no urine. Hardness and pain in the lower abdomen with difficulty in urination is termed Niase (dysuria/obstructed urination). Frequent passage of black stool indicates Accumulated Blood (Xuxue). Diarrhea accompanied by abdominal fullness is a critical condition (death prognosis). Constipation with hard, full abdomen and severe pain that cannot be pressed indicates Heat Binding (Rejie). Diarrhea is generally Cold, but can also be Heat, as stated in the classics: "Sudden violent diarrhea belongs to Heat." (The nature of Fire is rapid; food does not have time to transform before being expelled. The urgency is intense, with loud borborygmi, resembling crab foam. If Heat leaves with the diarrhea and Pain subsides with the relief, it may resolve spontaneously.) Another presentation is pure watery diarrhea, termed Rejie Pangliu (Heat binding with peripheral flow). (Dry fecal matter forms pellet-like masses inside, blocking waste, allowing only clear fluid to leak from the sides; the odor is extremely foul.) All these are Heat patterns. Additionally, duck-egg-consistency loose stools indicate Cold. Stool resembling moldy soybean paste, sticky (lacking visible undigested particles due to thermal digestion), and extremely foul-smelling indicates Heat.