The tongue can tell us an awful lot about our health – and scientists are now using AI to diagnose patients through tongue colour, according to Professor Luke O’Neill.
On The Pat Kenny Show this morning, the Trinity professor said doctors have documented seven different states your tongue can go through – each of which suggests a different malady.
He said a new study has used machine learning to teach artificial intelligence (AI) systems how to use the tongue to help diagnose patients – and found that the machine is capable of doing so with startling accuracy.
It means future patients may be able to stick out their tongue and take a picture that doctors can then use to diagnose issues with a basic app.
A woman with her tongue out. Image: Sergiy Zinkevych / Alamy“It turns out there are seven different colours that your tongue can go through and different colours indicate different health statuses and various things in your body,” said Prof O’Neill.
“It's like a little signal of what's happening inside your body really.”
Strawberry tongue
The first colour to watch out for is strawberry tongue.
“If it's bright red, that means you've got a nasty infection and in particular if it goes scarlet – remember scarlet fever,” said Prof O’Neill.
“Streptococcus pyogenes is the bug that makes your tongue go into a strawberry but secondly, more seriously, a thing called toxic shock syndrome, which can be very serious.
“If that happens, go and see a doctor. Toxic shock can be lethal.”
He said a red tongue is a sure sign that there is an infection somewhere in your body – causing your blood vessels to dilate and forcing the blood to rush to the tongue.
Blue tongue
The next colour to be aware of is blue tongue.
“If your tongue goes blue, that normally means some kind of blood flow problem somewhere, because less blood is flowing into your tongue and it begins to go a bit blue,” said Prof O’Neill.
“It can be heart problems, lung problems and eczema.
“It must be about your blood flow changing in your body and no longer flowing into your tongue.”
Yellow tongue
Prof O’Neill said yellow could be a sign of diabetes.
“You can imagine in ancient times, the Chinese or whoever would spot this,” he said. “Though they couldn't do much for you.
“Now though, doctors go, ‘Hang on a minute’ there's something funny about that tongue and it can help the doctors in terms of how they might treat you.”
White tongue
The Trinity professor said white tongue is a sign of anaemia.
“If you have very low iron, your blood is affected and the tongue can go a bit white because you're anaemic and that means you're iron deficient,” he said.
“That's not uncommon for older people especially; they sometimes get a bit anaemic and maybe the tongue has gone a bit paler, shall we say.
“That's an indication that you might want to get that checked out as well.”
Indigo and violet tongue
Prof O’Neill said a dark purple tongue can be a sign of asthma or an allergic reaction.
“Again, that must mean your breathing is affected,” he said.
“Your blood is getting constricted in your tongue and now the tongue goes a really dark purple – much darker than blue.
“That might mean a severe asthma situation or some kind of allergic reaction.”
Smooth tongue
If you notice your tongue has gone smooth, you might have a vitamin deficiency.
“So, it could be B Group vitamins for example,” said Prof O’Neill.
“Vitamin B or folic acid – you might know about folic acid from women who are trying to conceive; it's a very important hormone when you're trying to conceive because it stops neural tube defects.
“If your tongue is smooth, there's a chance you might be Folic Acid deficient – so watch for that smoothness.”
‘It’s like the rainbow’
Prof O’Neill said artificial intelligence was able to diagnose patients with 96.6% accuracy using pictures of their tongue.
He said that figure is “extremely accurate” when it comes to diagnosis and doctors now believe the programme could prove very useful as society shifts away from hospitals and back towards community care.
