Dra. Cléo Salustiano In this article
SummaryWhat causes canker sores on the tongue and how to tell them from other soresWhat helps, what to avoid and when to see a dentistFAQRead nextCanker Sore on the Tongue: Causes, How Long It Lasts and What to Do
Quick summary of this article+
A canker sore on the tongue is a painful, round sore with a white-yellow base and red border that usually heals on its own in one to two weeks. Minor injuries, stress, hormonal changes, irritating foods and personal predisposition are among the causes, and very frequent sores should be looked into with a physician. At home, it helps to avoid acidic and spicy foods, brush with a soft brush and rinse gently with salt water; pharmacy products only with professional advice and according to the package insert. A sore that does not heal in about two weeks, feels hard or keeps returning to the same spot needs to be examined. In Mooca, Dr. Cléo Salustiano (CRO-SP 170844) sees patients every day, from 8 a.m. to 10 p.m.
A canker sore on the tongue is a small, round sore with a white or yellowish center and a red border that stings, especially when eating and talking. In most cases it is not serious, is not contagious and heals on its own in about one to two weeks. Meanwhile, the goal is to ease the discomfort and avoid irritating the sore. The warning sign is a sore that does not heal in about two weeks, keeps coming back in the same spot or comes with fever and feeling unwell: in those cases, it needs to be assessed.
The tongue is a common place for canker sores because it moves all the time and touches the teeth. The tip, the sides and the area under the tongue are the most frequent spots. An accidental bite, the sharp edge of a broken tooth or filling, or rubbing from braces can be the starting point, and the dentist can identify and correct these local causes.
Dr. Cléo Salustiano (CRO-SP 170844), a dentist in Mooca, explains what causes canker sores on the tongue, how to tell them apart from other sores, what helps at home, what not to do and when to seek care.
This article comes from Dr. Cléo Salustiano's dental office in Mooca, São Paulo (care in English, Portuguese and Spanish). See the general dentistry page to learn how the treatment is done here and book your assessment.
What causes canker sores on the tongue and how to tell them from other sores
A canker sore (technically, an aphthous ulcer) has no single cause. It usually appears when several factors combine: minor injuries, such as biting the tongue or brushing too hard; stress and poor sleep; hormonal changes, such as around the menstrual period; very acidic or spicy foods in sensitive people; and personal predisposition, since canker sores run in some families. In some people, certain toothpaste ingredients also seem to trigger them.
When canker sores are very frequent, large or slow to heal, it is worth looking into general causes with a physician, such as low iron, vitamin B12 or folic acid, bowel conditions, immune changes and some other systemic conditions. In these cases, the sore is a sign that the body may need attention, and treating the cause usually reduces flare-ups.
Not every tongue sore is a canker sore. A traumatic ulcer appears right after a bite or rubbing and has a clear link to the cause. Cold sores (herpes) start as clustered blisters, usually on the lips. Transient lingual papillitis forms a painful red or whitish "bump" that disappears in a few days. Geographic tongue forms smooth patches that move around. And when the sore is on the gums, the advice is similar, as explained in the article canker sore on the gums.
The most important point: a tongue sore that does not heal in about two weeks, feels hard, bleeds easily, does not hurt (yes, that is also a warning sign) or appears with white or red patches that do not wipe off needs to be examined. Most of these lesions are benign, but an exam is the way to rule out more serious conditions, especially in people who smoke or drink alcohol often. The article mouth sore: what could it be gives a broader overview.
| What it looks like | What it may be | What to do |
|---|---|---|
| Round, painful sore with a white-yellow base and red border | Common canker sore | Home care; usually heals in 1 to 2 weeks |
| Sore that appeared right after a bite or contact with a broken tooth | Traumatic ulcer | Have the dentist correct the cause |
| Red or white "bump" on the surface that goes away in a few days | Transient lingual papillitis | Monitor; have it checked if it persists |
| Smooth patches that move around, no open sore | Geographic tongue | Assessment to confirm; it is benign |
| Sore that does not heal in ~2 weeks, feels hard or is painless | Lesion that needs a diagnosis | Assessment as soon as possible |
| Many sores with fever, feeling unwell or trouble swallowing | Infection or systemic illness | Urgent medical care |
What helps, what to avoid and when to see a dentist
While the canker sore heals, it may help to avoid acidic, salty, spicy or very hot foods; choose soft foods that are cool or at room temperature; drink plenty of water; brush with a soft toothbrush, taking care not to touch the sore; and rinse gently with warm water and a little salt, without rubbing the area. These steps do not speed up healing much, but they reduce day-to-day pain.
About "medicine for a canker sore on the tongue": pharmacies sell gels, ointments and topical solutions that can ease pain or protect the sore. The choice of product and how to use it should follow the advice of a physician, dentist or pharmacist and the package insert, taking into account allergies, pregnancy and other medications. When the pain is intense, the dentist assesses and may suggest ways to relieve it. Do not take anti-inflammatories or corticosteroids on your own.
What not to do: do not put aspirin, alcohol, vinegar, lemon or pure baking soda on the sore, do not try to "burn" it with caustic products and do not pick at it. These practices can burn the lining of the mouth and delay healing. Seek urgent medical care or go to the emergency room if there is high fever, many sores at once with feeling unwell, difficulty swallowing liquids (in children, a risk of dehydration) or difficulty breathing.
This content is for information only and does not replace an exam. Consult a dentist if the canker sore does not heal in about two weeks, if flare-ups are frequent or if you suspect a tooth or appliance is hurting your tongue. In Mooca, Dr. Cléo Salustiano sees patients every day, from 8 a.m. to 10 p.m., including Sundays and holidays, for general dentistry and dental emergencies in Mooca.
How long does a canker sore on the tongue last?
+
A common canker sore usually heals in about one to two weeks, and the pain tends to ease after the first few days. Larger sores may take longer. If it has not healed in about two weeks, it is best to have it examined.
Why do I get canker sores under my tongue?
+
The area under the tongue has thin lining and rubs against the lower teeth and, sometimes, tartar or filling edges. The usual general causes also apply, such as stress, minor injuries and irritating foods. If the sore keeps coming back in the same spot, the dentist checks whether something is hurting that area.
What can I use to treat a canker sore on my tongue?
+
There are topical products that ease pain and protect the sore, but the choice should be made with the advice of a physician, dentist or pharmacist and according to the package insert. Avoid taking anti-inflammatories or corticosteroids on your own, and never put aspirin, alcohol or other caustic products on the sore.
Is a canker sore on the tongue contagious?
+
No. A common canker sore is not caused by a transmissible virus and does not spread through kissing or shared cutlery. Herpes, which is sometimes confused with canker sores, is contagious and usually appears as clustered blisters, mostly on the lips.
Can a sore on the tongue be cancer?
+
A common canker sore is not cancer and does not turn into cancer. The warning sign is different: a sore that does not heal in about two weeks, feels hard, bleeds easily or does not hurt. These lesions need an exam, especially in people who smoke or drink often. Most turn out to be benign, but only an assessment can confirm it.
Can frequent canker sores point to a health problem?
+
They can. Sores that keep appearing, are large or are slow to heal may be linked to low iron, vitamin B12 or folic acid, bowel conditions or immune changes. It is worth talking to a physician to investigate and to a dentist to rule out local causes.
Where can I have a tongue sore checked in Mooca?
+
In Mooca, Dr. Cléo Salustiano (CRO-SP 170844) sees patients at Rua Hipódromo, 1141, near Bresser-Mooca station, Monday to Sunday, from 8 a.m. to 10 p.m., including holidays. Appointments via WhatsApp (11) 97409-7834, in Portuguese, English or Spanish.
