Mouth concern

Aphthous ulcers

Canker sores are common, painful, and usually benign — but recurrent or severe ulcers deserve a careful look.

What's actually going on

Aphthous ulcers are painful, shallow sores inside the mouth. They are not the same as cold sores. Flares can be triggered by trauma, stress, certain foods, dental products, nutritional deficiencies, inflammatory disease, or no obvious trigger.

What tends to help

  • Distinguishing canker sores from cold sores and other ulcers
  • Avoiding triggers when they are obvious
  • Prescription topical treatment when pain or recurrence is significant
  • Looking for red flags when ulcers are frequent, severe, or unusual

What I'd skip

  • Putting harsh chemicals or essential oils on mouth ulcers
  • Assuming every oral sore is herpes
  • Ignoring ulcers that persist or keep worsening

When to get in-person or urgent care

  • Ulcers lasting more than 2–3 weeks, unexplained weight loss, fever, eye/genital ulcers, or severe systemic symptoms
  • Trouble swallowing, dehydration, or immunosuppression
Talk to a dermatologist

Recurrent painful mouth ulcers?

Start a visit and Dr. Eckert can review the pattern and decide whether online management is appropriate or whether dental, primary care, or in-person evaluation is needed.

Start a visit

Supportive basics

These are supportive products and categories that may fit a simple routine. They are not a substitute for medical evaluation and are not intended to diagnose, treat, cure, or prevent this condition.

Recommended OTC option

A third-party product category Dr. Eckert may recommend when it fits your situation.

Coming soonAffiliate pick
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Barrier support

Simple moisturizing support to reduce friction and keep routines boring in the best way.

$30Supportive
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Prescription options require a visit. Treatment may include prescription medication only when medically appropriate. Some prescriptions may be sent to a licensed third-party compounding pharmacy for patient-specific preparation.