A white tongue can be a sign of dehydration or not having enough fluid in your body.
When youre dehydrated, your mouth becomes dry, leading to a build-up of bacteria on the tongue.
The bacteria can appear as a white coating on the tongue.
Ekaterina Goncharova / Getty Images
There are other causes of a white tongue.
Ekaterina Goncharova / Getty Images
What Does a Dehydrated Tongue Look Like?
If you are dehydrated, the saliva glands in your mouth wont produce as much fluid.
Reproduced with permission from © DermNetdermnetnz.org2023.
Other Symptoms With a Dehydration Tongue
A white tongue is not one of the primarysymptoms of dehydration.
An emergency room can quickly evaluate you for dehydration and help you rehydrate safely.
These can include a burn or bite thats healing.
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The causes below can also contribute to a white tongue orwhite spots in the mouth.
Oral Thrush
Oral thrushis a yeast-related infection that causes white spots in the mouth.
Its most common in babies and people with dentures, although anyone can develop it.
Reproduced with permission from © DermNet and © Professor Deborah Greenspandermnetnz.org2023.
If you have thrush, the white patches can be wiped away, though they will return.
This photo contains content that some people may find graphic or disturbing.
Reproduced with permission from DermNetdermnetnz.org2023.
Reproduced with permission from © DermNet and © Raimo Suhonendermnetnz.org2023.
Geographic Tongue
Geographic tongueis a harmless condition that causes bald patches on the surface of the tongue.
It can also cause white areas on the tongue and other discolorations.
Reproduced with permission from DermNet and Raimo Suhonendermnetnz.org2023.
Reproduced with permission from © DermNetdermnetnz.org2023.
The white patches cannot be wiped away.
Reproduced with permission from DermNet and Professor Deborah Greenspandermnetnz.org2023.
It can also include a white rash in the mouth and on the tongue.
Reproduced with permission from © DermNetdermnetnz.org2023
Reproduced with permission from DermNet and Raimo Suhonendermnetnz.org2023.
Ulcers
Ulcers are white wounds on the tongue or elsewhere in the mouth.
They generally resolve on their own, but can sometimes indicate a more serious condition.
For example, oral syphilis leads to these white ulcers on the tongue, as can tongue cancer.
However, a white tongue can be a sign of serious illness, including tongue cancer.
Summary
Dehydration can cause a white tongue over time.
Other common causes for white tongue, including oral thrush and tongue cancer.
Brigham and Womens Hospital.Coated/hairy tongue.
Harvard Health Publishing.Symptoms of dehydration: What they are and what to do if you experience them.
NHS.Sore or white tongue.
Institute for Quality and Efficiency in Health Care.Oral thrush: Overview.
American Academy of Oral Medicine.
Brigham and Women’s Hospital.
Division of Oral Medicine and Dentistry.Oral leukoplakia.
Le Cleach L, Chosidow O.Lichen Planus.N Engl J Med.
2012;366(8):723-32.
Memorial Sloan Kettering Cancer Center.Tongue cancer.
