White tongue

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Two days ago, I met a person who had a thick white coating on their tongue.  Wondering what it was called and its implications for health, I asked members of the e-Mair list about it.  Here are some of the answers I received:

Denis (Sinologist):

Thick tongue coating, often due to lengthening of the keratinous papillae on the tongue's surface.

Heidi (Yoga teacher and Ayurveda specialist):

We call it "ama" in Ayurveda – accumulated toxins from undigested foods. The person who has it might be ill. I scrape my tongue every day

From Proto-Indo-Aryan *HaHmás, from Proto-Indo-Iranian *HaHmás, from Proto-Indo-European *h₂eh₃mós (raw, uncooked), from *h₂eh₃- (to burn). Cognate with Ancient Greek ὠμός (ōmós, raw, crude, uncooked, undressed), Old Armenian հում (hum, raw, uncooked), Old Irish om (raw, uncooked) (whence Irish amh), Persian خام(xâm, crude, raw).


VHM:  In some Indic languages it means, among other things, "undigested", as Heidi noted for Ayurveda in general.

Diana S. Zhang (South Asian Studies graduate student):

We call it 舌苔 (shétái, “tongue moss”) in Chinese. It does indicate accumulated dietary toxins, but in Chinese medicine it even more suggests 心火 xīn huǒ (“heart fire") within that person — meaning that they must be extremely stressed, anxious, and in a high-strung mode for an extended period of time! Their “heart fire” must be owing to striving for a position or other much desired goal. Poor person! But, yes, they should scrape it off before meeting others (I scrape my tongue everyday!). Hygiene showcases one's capacity to take care of oneself and maintain professionalism under all circumstances. I wish this person the best of luck in their striving for achievement! I think I totally empathize with their 心火 xīn huǒ (“heart fire") illness because I’m under constant stress from workload, too.

I wonder if there's a name for this phenomenon in other languages.  We're linguists, after all, and are preoccupied with matters of the tongue.


Selected readings


  1. Anthony said,

    December 15, 2021 @ 8:04 pm


  2. Victor Mair said,

    December 15, 2021 @ 8:38 pm

    From Anthony's link:


    Thrush, a fungal infection of the mouth, happens most often to toddlers and children but can affect anyone. Antifungal medications, which are generally taken for 10 to 14 days, are often prescribed to treat thrush.
    What is thrush?

    Thrush is a fungal (yeast) infection that can grow in your mouth, throat and other parts of your body. In your mouth thrush appears as a growth that can look like cottage cheese – white, raised lesions on your tongue and cheeks. The condition can quickly become irritated and cause mouth pain and redness.

    Thrush is caused by the overgrowth of a type of fungus called Candida. Mouth and throat thrush is called oropharyngeal candidiasis.

    A thrush infection is annoying but it’s generally a minor problem for healthy people and will clear up in a few weeks with antifungal treatment.


    I think that the white coating on the tongue discussed in the o.p. is different from the fungal infection described in the link from the Cleveland Clinic. (I had heard of "thrush" before.)

  3. Keith Ivey said,

    December 15, 2021 @ 9:27 pm

    In English it's a coated tongue, as I remember from Bugs Bunny.

  4. DaveK said,

    December 15, 2021 @ 9:28 pm

    Assuming it isn’t thrush, it sounds like an extreme case of what Americans typically just call “morning mouth”—just the unpleasantness that builds up from your mouth being open during sleep. Dried saliva and whatnot accumulate and can be removed by brushing your tongue while brushing your teeth.

  5. wanda said,

    December 16, 2021 @ 12:05 am

    My first thought was thrush, also.
    Can anyone tell me what these supposed "toxins" are? And why they would come out on one's tongue??

  6. Pau Amma said,

    December 16, 2021 @ 12:30 am

    I'm thinking candidiasis (the fungal tongue or mouth infection), for which the general-public name in French is "muguet" (as a flower, "lily of the valley").

  7. Nigel said,

    December 16, 2021 @ 5:56 am

    I recently came across the phrase ‘geographic tongue’, which seems to refer to the same phenomenon

  8. Jonathan Smith said,

    December 16, 2021 @ 6:46 am

    Should be Mand. shétāi, i.e. second syllable not the same as 'moss' in this and much other Sinitic… seems trivial but could be significant for e.g. comparative reconstruction of lateral onsets.

  9. Lameen said,

    December 16, 2021 @ 8:58 am

    Interesting – so that's where Arabic khāmm "raw" in mawādd khāmm "raw materials" comes from, and why it doesn't take expected gender agreement.

  10. Victor Mair said,

    December 16, 2021 @ 11:28 am

    Interesting that 苔 meaning "moss; lichen" in Mandarin is 2nd tone (tái), but with the meaning "tongue coating / fur" is first tone (tāi). There are also slight differences in pronunciation between the two meanings in the other Sinitic topolects, yet surely they must be close cognates, in the sense of designating soft, hairy / furry growth on a moist, usually dark surface.


    "[Tongue] fur" was the English word for the phenomenon described in the o.p. that I was searching for and knew about, but had momentarily forgotten.

  11. David Marjanović said,

    December 16, 2021 @ 4:13 pm

    Persian خام‎ (xâm, “crude, raw”)

    By the way, that word is on the list of words where *h₂ is preserved in modern Persian (apparently randomly as /x/ or /h/, though, indicating some more complex history). See for example p. 5 of this paper and other works on Martin Kümmel's Academia page.

  12. R. Fenwick said,

    December 16, 2021 @ 10:24 pm

    @Nigel: I recently came across the phrase ‘geographic tongue’, which seems to refer to the same phenomenon

    "Geographic tongue" may look superficially similar, but it's actually the opposite: rather than an accumulation of material, geographic tongue is the irregular loss of normal epithelial tissue from the tongue surface as a result of inflammation. While both result in apparent contrasting-coloured patches, the "tongue moss" contrast is between whitish plaque and pinkish epithelium, where geographic tongue is between pinkish epithelium and reddish inflammation.

    I imagine it's just difficult to distinguish the two at first glance because there's so much variety in tongue shape and colour to begin with.

  13. Victor Mair said,

    December 16, 2021 @ 10:59 pm

    From Zihan Guo:

    Your instinct was right that the tongue reveals much about one's health, hence the important "tongue diagnosis" shézhěn 舌診 in Traditional Chinese medicine (TCM). The Sù wèn 素問 ("Plain Questions") chapter of Huángdì nèijīng 黃帝內經 (Yellow Emperor's Internal Classic) has lines like xīn zhǔ shé 心主舌 ("the heart rules over the tongue")… zài qiào wéi shé 在竅為舌 ("of the orifices, [the supernatural powers] create the tongue [i.e., the palate]").* The white stuff on one's tongue usually indicates problems with pí 脾 ("spleen") & wèi 胃 ("stomach"), leaving them susceptible to shīqì 濕氣 ("dampness"), further divided into shīhán / shīrè 濕寒 / 濕熱 ("damp cold / damp heat"). With a weak wèi 胃 ("stomach"), one cannot digest food well. With a weak pí 脾 ("spleen"), one accumulates erosive shīqì 濕氣 ("dampness"), as the pí 脾 ("spleen") absorbs and distributes liquids. Besides the white shétāi 舌苔, people affected by shīhán 濕寒 ("damp cold") also tend to have thick tongues with indentations on the sides, which we call chǐhén 齒痕 ("tooth marks").

    *5.27. See Ilza Veith, Huang Ti Nei Ching Su Wên: The Yellow Emperor's Classic of Internal Medicine, new ed. (Berkeley and Los Angeles: University of California Press, 1966), p. 119.

    My father's friend is a qualified Zhōngyī 中醫 (traditional Chinese doctor) and an Yì jīng 易經 (I ching specialist). I used to watch him perform "tongue diagnosis" and hear him explain all this. Part of why I am interested in TCM.

  14. DMT said,

    December 19, 2021 @ 4:57 am

    See here for the history of tongue diagnosis in Chinese medicine, with particular reference to the history of illustrating the various diagnostic appearances of the tongue. Also here (in Japanese) for the history of how these traditions were received and adapted in Japan.

  15. DMT said,

    December 19, 2021 @ 6:54 am

    Oops – messed up the links… Here they are:

  16. Philip Taylor said,

    December 19, 2021 @ 8:19 am

    "Here" would benefit from a hyperlink, DMT, in both instances.

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