What is a mouth sore? A mouth sore is any break, ulcer, or lesion in the soft tissue of the mouth, including the lips, cheeks, gums, tongue, and floor or roof of the mouth. Most mouth sores are harmless and heal within one to two weeks. However, some require professional evaluation, particularly sores that persist beyond 14 days, as they may indicate a more serious condition.
If you have a mouth sore that is not healing, contact Saratoga Smiles for an evaluation.
What Are the Most Common Types of Mouth Sores?
Canker Sores (Aphthous Ulcers)
Canker sores are small, shallow ulcers that appear inside the mouth. They are not contagious. They typically appear as round or oval sores with a white or yellow center and red border. Triggers include stress, acidic foods, minor mouth injuries (biting your cheek), hormonal changes, and nutritional deficiencies (B12, iron, folate).
Most canker sores heal on their own within 7 to 14 days. Over-the-counter topical treatments, saltwater rinses, and avoiding spicy or acidic foods can reduce discomfort.
Cold Sores (Fever Blisters)
Cold sores are caused by the herpes simplex virus (HSV-1) and typically appear on or around the lips. Unlike canker sores, cold sores are contagious. They begin as tingling or burning, then form fluid-filled blisters that eventually crust over and heal in 7 to 10 days. Antiviral medications can shorten outbreaks.
Oral Thrush (Candidiasis)
Oral thrush is a fungal infection that produces white, creamy patches on the tongue or inner cheeks. It is more common in seniors, denture wearers, patients with dry mouth, and those using inhaled corticosteroids. Treatment involves antifungal medication prescribed by your dentist or physician.
When Should I See a Dentist About a Mouth Sore?
See your dentist if a sore lasts longer than two weeks without healing; a sore is unusually large or spreading; you have recurring sores that appear frequently; a sore is accompanied by fever, difficulty swallowing, or swollen lymph nodes; or you notice a white or red patch that does not go away.
Persistent, non-healing mouth sores can be an early sign of oral cancer. Early detection is critical, and our comprehensive dental exams include oral cancer screening.
How Can I Prevent Mouth Sores?
- Maintain good oral hygiene with gentle brushing and flossing
- Avoid foods that trigger canker sores (citrus, spicy foods, chips)
- Manage stress through exercise, sleep, and relaxation techniques
- Stay hydrated and address dry mouth proactively
- Replace worn toothbrushes that may irritate gum tissue
- Visit your dentist regularly for screening and preventive care
Frequently Asked Questions
Are canker sores contagious?
No. Canker sores are not caused by a virus and cannot be spread from person to person. Cold sores (caused by HSV-1) are contagious.
Can stress cause mouth sores?
Yes. Stress is one of the most common triggers for canker sores. Stress can also trigger cold sore outbreaks in people who carry HSV-1.
What does oral cancer look like?
Oral cancer can appear as a persistent sore that does not heal, a white or red patch, a lump, or unexplained numbness. Any mouth sore lasting more than two weeks should be evaluated.
Should I use mouthwash on a mouth sore?
Avoid alcohol-based mouthwash, which can irritate sores. Saltwater rinses (1/2 teaspoon salt in 8 ounces of warm water) are gentler and equally effective.
Reviewed by Dr. Richard Dennis, Saratoga Smiles, 6 Carpenter Lane, Saratoga Springs, NY 12866.