Canker sores, also known as aphthous ulcers, are small, shallow sores that appear on the soft tissues inside your mouth. They often show up on the inner lips, cheeks or tongue and look like a white or yellow oval with a red border. They are not contagious, but they can make eating, drinking and talking uncomfortable.

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Most canker sores heal without treatment, but understanding your triggers and using the right remedies can ease pain and prevent future flare‑ups.

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What Canker Sores Are and Why You Get Them

Canker sores are inflammatory ulcers. They are not caused by viruses, so you cannot pass them on. They usually develop due to a combination of factors.

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Common triggers

Minor mouth injuriesStress or fatigueAcidic or spicy foodsHormonal changesNutritional deficienciesToothpaste containing sodium lauryl sulphate (SLS)

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How common are they in the UK

A UK study on recurrent aphthous stomatitis found that 47.2 percent of people surveyed had experienced canker sores in the past six months.

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If you get recurring sores, identifying your personal triggers is the most effective way to reduce flare‑ups.

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Immediate Relief with At‑Home Remedies

Most canker sores can be managed at home. These simple remedies help clean the ulcer, reduce inflammation and ease discomfort.

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Saltwater rinse

• Salt acts as a natural antiseptic.

• Mix half a teaspoon of salt in warm waterSwish gently for thirty secondsRepeat two to three times a day

• Saltwater temporarily changes your mouth’s pH, making it less friendly for bacteria.

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Milk of magnesia

Dab a small amount directly onto the sore. It forms a protective layer and reduces irritation.

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Black tea bag

Black tea contains tannins that help dry the sore and reduce pain. Press a damp tea bag against the ulcer for a few minutes.

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Extra care if you wear aligners

Saltwater rinses help keep your mouth clean and prevent irritation under aligner trays.

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Over‑the‑Counter Treatments That Work

If home remedies are not enough, UK chemists offer several effective options.

Pro tip

Dry the area with a tissue before applying gels or pastes. This helps them stick and form a proper seal.

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Preventing Future Canker Sores

Once the pain settles, prevention becomes the priority.

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Manage stress

Stress is a major trigger. Mindfulness, exercise and better sleep can reduce flare‑ups.

^{NHS mental health support}

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Identify food triggers

Common triggers include:

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• Citrus fruits

• Tomatoes

• Spicy foods

• Nuts

• Chocolate

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Keep a food diary to spot patterns.

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Check your toothpaste

Sodium lauryl sulphate (SLS) can irritate sensitive mouths. Switching to an SLS‑free toothpaste helps many people.

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Gentle brushing

Use soft bristles and circular motions to avoid micro‑injuries.

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Support your nutrition

Deficiencies in iron, zinc or B vitamins can contribute to recurring sores.

NHS nutrition guidance

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When to See a Dentist

Most canker sores heal within one to two weeks. Seek professional advice if you notice:

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•Sores lasting longer than three weeks

• Unusually large or deep ulcers

• Constant recurrences

• Pain that stops you eating or drinking

• Ulcers accompanied by fever or rash

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A dentist can prescribe stronger treatments such as antimicrobial mouthwash or corticosteroid ointment.

Toothfairy offers fast access to UK dentists through virtual consultations

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The Future of Canker Sore Treatment

New UK research has identified ninety‑seven genetic variations linked to canker sore susceptibility. These findings highlight the role of the immune system and may lead to targeted therapies in the future.

UK genetic research

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Frequently Asked Questions

Are canker sores contagious

No. They are not caused by viruses and cannot be passed on.

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How long do they last

Minor sores heal in one to two weeks. Major sores can take up to six weeks.

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Can food cause canker sores

Yes. Acidic, spicy or abrasive foods can trigger ulcers in sensitive mouths.

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Do clear aligners make them worse

New aligners can cause temporary irritation. Toothfairy dentists can advise on adjustments and comfort tips.

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Take Control of Your Oral Comfort Today

Canker sores are common, but with the right care you can ease pain quickly and reduce future flare‑ups. If you need fast advice, emergency support or cosmetic guidance, Toothfairy connects you with qualified UK dentists directly through your phone.

Start your oral health journey

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