Recurrent ulcers on the tongue are usually due to a mix of local irritation, minor immune reactions, and (sometimes) underlying health issues, but they are rarely dangerous; persistent or very frequent ulcers do need a medical or dental check.

Common everyday triggers

Several day‑to‑day things can repeatedly injure or irritate the tongue and set off ulcers.

  • Accidentally biting the tongue, especially if teeth are sharp or slightly misaligned.
  • Rubbing from braces, retainers, rough fillings, broken teeth, or dentures.
  • Burns from very hot food or drinks and irritation from very spicy or acidic foods.
  • Hard‑bristled toothbrushes or strong mouthwashes/toothpastes (for example those with sodium lauryl sulfate).

If the same spot on the tongue keeps being rubbed or bitten, an ulcer can keep coming back in that exact area.

Body factors that make ulcers recur

Even without obvious trauma, some people are simply more prone to tongue and mouth ulcers.

  • Stress and fatigue are classic triggers; flares often happen during exams, busy periods at work, or illness.
  • Hormonal changes (for example around periods or pregnancy) can increase frequency in some people.
  • Genetic tendency: some families just get recurrent “canker sores” more often.
  • Stopping smoking can temporarily increase mouth ulcers as your mouth lining adjusts.

These factors often act on top of minor tongue injuries, making ulcers more likely and slower to heal.

Possible underlying health causes

Repeated or multiple ulcers, especially with other symptoms, can sometimes signal a deeper issue.

  • Vitamin deficiencies, especially B12, folate, iron and sometimes other B vitamins.
  • Gastrointestinal or autoimmune conditions such as coeliac disease, Crohn’s disease, ulcerative colitis, lupus, Behçet’s disease.
  • Weakened immune system (for example from certain chronic illnesses, including HIV or lupus).
  • Infections such as herpes simplex, gingivostomatitis, or oral thrush can cause tongue ulcers or painful sores.
  • Very rarely, chronic or non‑healing tongue lesions can be due to precancerous changes or oral cancer, especially if they are hard, irregular, or painless and last more than 3 weeks.

If ulcers are frequent and you feel generally unwell, have weight loss, fevers, gut symptoms, or skin/genital sores, a medical review and blood tests are important.

What you can do at home

Mild recurrent tongue ulcers can often be eased and reduced with simple steps.

  • Switch to a soft‑bristled toothbrush and avoid toothpastes with sodium lauryl sulfate if you notice a link.
  • Avoid obvious triggers: very hot food/drink, sharp crisps, strongly acidic or very spicy foods that sting existing ulcers.
  • Rinse with warm salt water or an alcohol‑free antiseptic mouthwash to reduce soreness and secondary infection risk.
  • Use topical gels, pastes, or mouth rinses specifically for mouth ulcers (often contain a mild steroid, anesthetic, or protective barrier) as directed by a pharmacist or doctor.
  • Look after general health: regular sleep, stress management, balanced diet with enough iron and B vitamins.

Most simple ulcers heal within about 7–14 days and do not leave scars.

When to see a dentist or doctor

Some patterns mean you should get checked rather than just waiting it out.

  • Any ulcer on the tongue or in the mouth lasting longer than 2–3 weeks.
  • Very frequent recurrences (for example, new ulcers almost every month or most of the time).
  • Large, very painful ulcers, many ulcers at once, or ulcers plus fevers, rash, genital sores, eye redness, or gut symptoms (diarrhea, blood, weight loss).
  • A patch or ulcer that is hard, raised, bleeds easily, or looks very different from usual canker sores.

A dentist or doctor can check for local causes (like sharp teeth), treat infection if present, and organize blood tests for anemia and vitamin levels, or refer to a specialist if anything more serious is suspected.

Information gathered from public forums or data available on the internet and portrayed here.