When was the last time you had a really good look in your mouth? Most of us barely give it a second glance after we’ve finished brushing and using a bit of floss. But getting to know what your tongue should look like on a good day – pink, moist and slightly rough from the tiny bumps containing the taste buds – means a better chance of spotting any worrying changes.
Victoria Sampson, a functional dentist and researcher who treats patients at oral care health centre The Health Society, says: “The mouth is a gateway to the rest of the body and not a single entity. It’s the second largest microbiome after the gut and the most diverse – it has over 700 different species of bacteria, which makes two billion bacteria in the mouth. When there is more bad bacteria than good, tooth decay, gum disease, ulcers and bad breath can occur.”
These gum disease-causing bugs can also cause damage in the rest of the body, with research showing an imbalanced oral microbiome is connected to over 50 conditions from Alzheimer’s to colorectal cancer, diabetes and heart disease. The tongue itself can also hold important clues to your overall health, an approach long used by traditional Chinese medicine (TCM).
In 2024, researchers even used AI to classify tongue colours to predict conditions including diabetes, asthma, Covid and anaemia with 96.6 per cent accuracy. “It’s like being a detective,” says Mahesh Kumar, a consultant maxillofacial surgeon and president of the Mouth Cancer Foundation. “You can often infer wider health problems from symptoms in the mouth. See a dentist who can give you an oral health check-up and spot any lesions, such as an ulcer, a white patch or red patch.”
Here, we ask the experts to explain exactly what your tongue is trying to tell you.
Pale smooth tongue: You could be anaemic
If your tongue is looking paler than usual, it could be a sign that you have iron deficiency anaemia, where the body can’t produce enough haemoglobin.
“People affected with anaemia lose the normal bumps on the tongue, so the tongue will be shiny and flat,” says Mr Kumar. “They will have a pale face and the inside of the mouth will have the same pallor.”
Other symptoms include fatigue, shortness of breath and cold hands and feet. People who are anaemic are usually treated with iron supplements, and advised to eat iron-rich foods such as liver, red meat, fortified cereals, legumes, spinach and tofu.
A white coating: Thrush or diabetes
A white coating or cottage-cheese like patches on your tongue, inner cheeks and throat could be oral thrush, a common fungal infection caused by an overgrowth of the yeast candida albicans. It could be a sign that you have undiagnosed or poorly controlled type 2 diabetes, with the sugar in your saliva feeding the yeast.
“With type 2 diabetes, blood sugars are high, your immune system is low and healing is poor,” says Mr Kumar.
Other symptoms of oral thrush, which can affect people with a weakened immune system, are soreness, a bad taste in the mouth or even a loss of taste. It’s treated with liquid antifungal medication that is held in the mouth for as long as possible.
Red, beefy-looking tongue: You might need to increase your B vitamins
A red, smooth, sore tongue suggests you’re not getting enough vitamin B12, which is needed to make DNA, create healthy red blood cells and maintain the nervous system.
We get vitamin B12 from eating meat, poultry, seafood, oily fish, eggs and dairy. Vegans can struggle to consume enough B12, and some people have pernicious anaemia, a medical condition which means they can’t absorb it.
“Vitamin B12 deficiency can cause a condition called atrophic glossitis [where the tongue’s bumps shrink, causing it to become smooth]” says Dr Vikas Prinja, a London-based dental implant surgeon.
“A healthy tongue is usually pink with a slightly rough surface, but in B12 deficiency it can become smooth and intensely red – often described as having a ‘beefy red’ appearance. Treatment depends on the cause and can include vitamin B12 injections or supplements, as well as a B12-rich diet.”
Persistent ulcers: Stress, low immune system or, rarely, cancer
Although annoying and sometimes extremely painful, mouth ulcers are common and usually nothing to worry about. “Ulcers are the loss of the epithelium, the top layer of skin, due to trauma from sharp teeth or fillings,” says Mr Kumar. “You can also get them when you’re run down, as the epithelium can break down when your immune system is low. People who are on chemo, are malnourished or highly stressed will be prone to mouth ulcers.”
So when should you worry? “Ulcers usually heal after a week to 10 days. But if you have an ulcer, white patch, red patch, bump or lump which has been present for three weeks, see your GP and get an urgent cancer referral.”
According to the Mouth Cancer Foundation, 10,825 people in the UK were diagnosed with mouth cancer last year, with cases rising by 49 per cent over the past 10 years, and 33 per cent of oral cancers occur on the tongue.
“We’re seeing mouth cancer in younger people, which we think is partly related to binge-drinking” says Mr Kumar. Smoking increases the risk, as does chewing paan – a mixture of tobacco and red betel nut that is popular among South Asian communities.
Cancer Research reports that mouth cancer has a 60 per cent survival rate, but the greatest challenge is early diagnosis – catching it before it has spread to the lymph nodes. Treatment is usually surgery, says Mr Kumar, with radiotherapy sometimes given after surgery.
Red patches with pale borders: Stress or hormone changes
If your tongue has red shapes marked out on it, you have geographic tongue.
“Geographic tongue is a harmless condition where smooth red patches with pale borders appear on the tongue, giving it the appearance of a map,” says Dr Sampson. “The patches can move and change over time and may have some mild sensitivity to spice or acidic foods, though most have no symptoms. It is not infectious or dangerous and usually doesn’t need treatment.
“Whilst the exact causes are still unknown, it is thought to be related to genetics and immune health. It is most common in people who suffer from stress, hormonal changes, or are immunocompromised, such as pregnant people or those suffering from psoriasis.”
White lacy lines or a painful blister: An inflammatory condition
White lacy marks on the tongue and inside the mouth could mean that you have lichen planus, an inflammatory condition, affecting one in 200 people. “Lichen planus can cause white areas and red patches on the tongue. You may have spots on the skin as well as a rash in the mouth,” says Mr Kumar.
Thick white or greyish patches: Potentially oral cancer
A long-lasting white patch (rather than all-over coating) on the tongue or other parts of the mouth that can’t be wiped off is your sign to go to the doctor.
“Leukoplakia is a persistent white patch in the mouth that cannot be wiped off, unlike thrush,” says Sampson. “It shows precancerous changes, with approximately 15 per cent of patients with leukoplakia developing oral cancer. White patches on the sides or underside of the tongue in smokers or heavy drinkers hold a higher risk of oral cancer.”
She advises visiting the dentist who may then refer you for a biopsy.
A dry and grooved tongue: You aren’t making enough saliva
A dry, cottony mouth and the grooved fissured look of the tongue (called xerostomia) can have more serious causes than just a blocked nose or catching flies overnight.
“Cancer treatment, diabetes, autoimmune conditions and menopause can all give you a dry mouth,” says Mr Kumar. “Another cause is Sjögren’s syndrome, an autoimmune disorder where the immune system attacks moisture-producing glands, affecting the eyes and mouth so you don’t make enough saliva. It’s treated with immunosuppressants and there are drugs that increase saliva production. You must also keep well hydrated.”
Lumps and bumps: An STI
It might sound alarmist, but if you’ve been travelling and had unprotected sex, there is a chance that you have contracted syphilis. “People go abroad and return to Europe without realising that they’ve contracted this STI,” says Mr Kumar. “The symptoms include lumps and bumps on their tongue.”
Other symptoms include swollen lymph nodes, a rash and flu-like symptoms that sometimes don’t appear until weeks after infection. Antibiotics are required.
Visit thehealthsociety.co.uk for more information