What your tongue can reveal about the state of your health
We use our tongues to taste, swallow and communicate, but they can also tell us a lot about our health – without saying a word.
There’s a reason doctors are always asking us to open our mouths and say “ahh”.
Beyond its primary functions of taste and speech, the tongue is also silently communicating important information about overall wellbeing.
Here’s what it can reveal about our health.
What does a healthy tongue look like?
Co-deputy chair of the Royal Australian College of General Practitioners Victoria Council Dr Aadhil Aziz says every tongue is unique.
“But, in general, a healthy tongue should be pinkish and moist,” Dr Aziz says.
He says significant changes in the appearance of the tongue can be an indication of an underlying condition.
Can your tongue warn you about illness?
New research has confirmed the tongue can be remarkably accurate as a diagnostic tool.
In the groundbreaking study by Australian and Iraqi researchers, computer scientists used a web camera to compare pictures of tongues against a database of 9000 images and were able to predict diabetes, renal failure and anaemia with 94 per cent accuracy.
The results come as no surprise to traditional Chinese medicine practitioner Eli Huang, who says the tongue has been used to detect illness and imbalances in the body for thousands of years.
“A very pale tongue may indicate a deficiency of qi and energy, as seen in chronic fatigue, or poor circulation of blood, as observed in cases of anaemia,” Eli says.
“A purple tongue could be indicative of chronic pain or poor blood circulation, while a red tongue indicates excess heat in certain organs such as the heart and stomach.”
Other changes in tongue shape and colour to watch for
Hairy tongue
It sounds horrifying, but a hairy tongue is a temporary, harmless condition that affects about 13 per cent of the population due to poor oral hygiene, medication or chronic antibiotic use.
The tongue can appear black because of certain types of bacteria and yeast – known as “black hairy tongue” – but it can also be brown, tan, green, yellow or white.
Bright red tongue
A bright red tongue could be due to a vitamin B12 deficiency or a sign of Kawasaki disease – a rare illness most common in children under 5.
“If your tongue is much redder than normal, or swollen, it can also be a sign of fever or infection,” Dr Aziz says.
Crooked tongue
A 2012 study found a crooked tongue can be an early warning sign of a stroke.
Dark red tongue
A 2022 study analysing smartphone images of the tongues of patients with COVID-19 infection showed almost 99 per cent of patients with a severe infection had a dark red tongue.
Dry tongue
Dr Aziz says tongue moisture can signal hydration levels, so a dry tongue often means you are dehydrated.
White tongue
A white and fuzzy coating on the tongue is usually the result of oral thrush, a fungal infection of the mouth.
Red or white patches on tongue
Red or white patches on the tongue can be a sign of mouth cancer, and you should consult a doctor.
Yellow tongue
Research has linked a yellow tongue coating to diabetes and gastritis.
Dr Aziz says it’s important to remember the tongue is only one piece of the health puzzle.
“There are a range of diseases that can be indicated on the tongue, but we don’t diagnose in isolation – the tongue is just part of the bigger picture,” he says.
“When in doubt, you should always check with your specialist general practitioner – that’s what they are trained for.”
More health indicators to look out for:
- How to decode your body’s tell-tale messages for better health
- The tell-tale signs of an iron deficiency
- Signs perimenopause has started and how to deal with it
- How knowing the signs of a stroke could save a life
Written by Dimity Barber.
