Dry mouth · kou zao

Also rendered: Dryness of the mouth (Literal) · Dry mouth (Clinical)

Reviewed · 2026-10-28

At a glance

Pinyin: kǒu zào
Simplified: 口燥
Literal: 口 kǒu, the mouth; 燥 zào, dry. The book keeps it apart from thirst: a patient may be dry and not want to drink, and that difference is the whole diagnosis in one of the two places the phrase occurs.
Shuowen: **《說文》：「燥，乾也。」从火，喿聲。「口，人所以言食也。」****底本二見**（3-28、4-09）。**同在卷三卷四，而所因不同**：3-28 少陰受病，熱灼腎水，故口燥舌乾而渴，燥與渴並見；4-09 濕家誤下，津不上承，故渴欲得水而不能飲，口燥而煩，燥與渴分。**口燥與口渴之别**：燥言口中無津，渴言欲飲；有燥而不欲飲者，正濕家之證。

In brief

The mouth dry for want of fluid. The book uses it twice, and the two uses divide the word: in lesser yin disease the dryness comes with thirst and a dry tongue, because heat is burning the kidney water; in the dampness patient it comes with a wish for water that cannot be drunk, because the fluid will not rise. Dryness with thirst and dryness without it are not the same complaint.

Senses in the classical corpus

The dryness of lesser yin 口燥舌乾而渴

少陰受病，熱灼腎水，故口燥、舌乾而渴；三者並見，知熱在裏

When the pulse at both positions is deep, lesser yin has taken the illness, on the fifth or sixth day: its vessel runs through the kidney, joins the lung and binds at the root of the tongue, so the mouth is dry, the tongue dry, and there is thirst.

尺寸俱沉者，少陰受病也。當五六日發，以其脉貫腎，絡於肺，繫舌本，故口燥舌乾而渴 — 傷寒論·傷寒例第三

Dryness that will not drink 渴欲得水而不能飲，則口燥煩也

濕家誤下，津液不上承，故雖渴而不能再飲，口燥而煩

He wishes for water and cannot drink it, and the mouth is dry and irritable: the fluid will not rise, so thirst and dryness stand apart.

渴欲得水而不能飲，則口燥煩也 — 傷寒論·辨痓濕暍脉證第四

Occurrences in the classics

Passages where the term does real work, with the original, pinyin and English on the same line.

Display

2 passages

傷寒論·傷寒例第三 Read in context →

尺寸俱沉者，少陰受病也。當五六日發，以其脉貫腎，絡於肺，繫舌本，故口燥舌乾而渴。尺寸俱沉者，少阴受病也。当五六日发，以其脉贯肾，络于肺，系舌本，故口燥舌干而渴。

chǐ cùn jù chén zhě shào yīn shòu bìng yě dāng wǔ liù rì fā yǐ qí mài guàn shèn luò yú fèi xì shé běn gù kǒu zào shé gān ér kě

When both inch and cubit are deep, the lesser yin is diseased; it shows on the fifth or sixth day. Its vessel threads the kidney, nets the lung, and ties the root of the tongue, and so the mouth is dry, the tongue parched, and there is thirst.

**「口燥」五篇共2見**（經文，不含成注），本文引第3篇第28段、第4篇第09段。

傷寒論·辨痓濕暍脉證第四 Read in context →

濕家，其人但頭汗出，背強，欲得被覆向火。若下之早，則噦，胃滿，小便不利，舌上如胎者，以丹田有熱，胸中有寒，渴欲得水而不能飲，則口燥煩也。湿家，其人但头汗出，背强，欲得被覆向火。若下之早，则哕，胃满，小便不利，舌上如胎者，以丹田有热，胸中有寒，渴欲得水而不能饮，则口燥烦也。

shī jiā qí rén dàn tóu hàn chū bèi qiáng yù dé bèi fù xiàng huǒ ruò xià zhī zǎo zé yuě wèi mǎn xiǎo biàn bù lì shé shàng rú tāi zhě yǐ dān tián yǒu rè xiōng zhōng yǒu hán kě yù dé shuǐ ér bù néng yǐn zé kǒu zào fán yě

A person with dampness disease sweats only from the head, has stiffness of the back, and wants to be covered and to sit by a fire. If purged too early, hiccup, fullness of the stomach and difficult urination follow; a coating on the tongue indicates heat below in the elixir field and cold above in the chest, so that he is thirsty and wants water yet cannot drink, leaving the mouth dry and the mind restless.

口燥二見：一與渴俱，一與渴分；同字而異因，濕家之燥最易誤作熱。

Compounds built on this term

口燥舌乾

kǒu zào shé gān

dry mouth and dry tongue

傷寒例第三

口燥煩

kǒu zào fán

dry mouth with irritation

辨痓濕暍脉證第四

口燥而渴

kǒu zào ér kě

dry mouth with thirst

傷寒例第三

How it has been translated

Every rendering below is a decision about which reader is being addressed. There is no neutral option.

This site	dry mouth	keeps it apart from thirst
Literal	mouth parched	exact, and stronger than the Chinese
Clinical	xerostomia	precise, and modern

Entry status

Review pending — who reviews this?

2026-10-28

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