What Causes Mouth Ulcers (and How to Ease Them)

A mouth ulcer has a way of making itself known at the worst possible time, whether that’s mid-meal or right before an important conversation. Most are harmless and clear up on their own, but that doesn’t make the sting any less annoying while they’re around. Understanding what causes mouth ulcers can help you spot patterns, ease the discomfort a little faster, and know when one is worth mentioning to your general dentist rather than waiting it out.

The Short Answer: Usually Minor Injury or Irritation

Most single mouth ulcers come down to some kind of minor trauma or irritation to the soft tissue inside the mouth. Common examples include:

• Accidentally biting the inside of your cheek or lip
• A sharp edge on a tooth, filling or brace catching the tissue
• Brushing too hard with a firm-bristled toothbrush
• Irritation from a strong mouthwash or toothpaste ingredient

Recurring ulcers, on the other hand, sometimes point to something a bit more specific, which is covered further down.

Common Triggers for Ulcers

Beyond physical injury, a few other common triggers for ulcers show up regularly:

• Stress or periods of poor sleep
• Hormonal changes
• Acidic, spicy or rough-textured foods
• Vitamin or mineral deficiencies, such as low iron, folate or B12
• Certain medications

Not everyone reacts to the same triggers, so it can help to keep a rough note of what was going on before an ulcer appeared, particularly if they keep coming back. If acidic or spicy food seems to be a factor, our list of tooth-friendly snacks has some gentler options worth trying instead.

What Are Recurring Mouth Ulcer Causes?

If ulcers keep appearing rather than being a one-off, it’s worth looking a little closer at what might be behind it.

Aphthous Ulcers

Aphthous ulcers, sometimes called canker sores, are a common type of recurring ulcer with no single identified cause, and they’re often part of the picture when people ask what causes mouth ulcers that keep coming back. According to Healthdirect, around 1 in 5 people experience recurrent mouth ulcers, and they tend to be more common during periods of stress or hormonal change.

Underlying Health Factors

Less commonly, ongoing or unusually persistent ulcers can be linked to a nutritional deficiency or an underlying condition affecting the digestive or immune system. This isn’t the case for most people, but it’s part of why a dentist or doctor may ask some broader questions if ulcers are frequent or slow to heal.

Easing Ulcer Discomfort at Home

While most ulcers heal on their own within one to two weeks, a few simple habits can help with easing ulcer discomfort at home in the meantime:

• Rinse gently with warm salt water a few times a day
• Avoid very hot, spicy or acidic foods while the ulcer heals
• Switch to a soft-bristled toothbrush temporarily if brushing near the area is uncomfortable
• Consider an over-the-counter gel or rinse designed for mouth ulcers, checking with a pharmacist first
• Avoid alcohol-based mouthwash until the ulcer has settled

When Ulcers Need Medical Attention

Most mouth ulcers don’t need anything beyond time and a bit of home care, but working out when ulcers need medical attention comes down to a few warning signs. It’s worth having one checked if:

• It hasn’t healed after around two weeks
• It’s unusually large or particularly painful
• Ulcers keep recurring frequently
• You notice several ulcers at once, or they appear alongside fever or swollen glands
• The ulcer bleeds easily or looks different to previous ones you’ve had

If pain becomes severe or you’re struggling to eat or drink, treating it as an urgent dental matter rather than waiting for a routine appointment is a reasonable call.

Better Health Channel’s guide to mouth ulcers notes that ulcers lasting longer than two weeks, or ulcers that don’t respond to usual home care, are worth having assessed by a dentist.

How Oral Hygiene Habits Affect Ulcers

Good oral hygiene doesn’t cause ulcers, but the way you brush can sometimes contribute to the physical irritation that triggers one. A gentler brushing technique and a soft-bristled brush can reduce this risk over time. Your dental hygienist can check your technique and flag any sharp edges on teeth or dental work that might be contributing to repeated irritation in the same spot.

Frequently Asked Questions

Are Mouth Ulcers Contagious?

No, ordinary mouth ulcers aren’t contagious. This is different to cold sores, which are caused by a virus and can spread. This information is general in nature, so if you’re unsure which type you’re dealing with, a dentist can help clarify.

Can Stress Really Cause Mouth Ulcers?

Stress is a commonly reported trigger for some people, though the exact relationship varies between individuals. If ulcers seem to line up with stressful periods, it may be worth mentioning this pattern to your dentist.

Should I See a Dentist for Every Mouth Ulcer?

Not necessarily. Most single ulcers settle on their own within a couple of weeks. This is general guidance, so persistent, unusually painful, or frequently recurring ulcers are the ones worth having assessed.

Can Children Get Recurring Mouth Ulcers Too?

Yes, children can experience recurring ulcers as well, and the common triggers are broadly similar to those in adults. If your child’s ulcers seem frequent or particularly bothersome, flagging it at their next dental visit is a reasonable step.

Do You Check Mouth Ulcers at Your Butler Clinic?

Yes, our team can take a look at persistent or concerning ulcers as part of general dental care at our dental clinic Butler WA families visit. As with any oral health concern, an in-person assessment is the most reliable way to understand what’s going on.

Book a Check-Up if Ulcers Keep Returning

If mouth ulcers have become a regular occurrence, or one just isn’t healing the way you’d expect, our team is happy to take a look and talk through what might be contributing. Book an appointment online to get started, or reach out to the practice with any questions beforehand.