Also known as a canker sore or salt blister, is an ulcer that occurs on the mucous membrane of the oral cavity.
A mouth ulcer, also called a canker sore, is a small, painful lesion that forms on the soft tissues inside the mouth. These sores develop on the inner cheeks, lips, tongue, gums, or the roof of the mouth. Mouth ulcers are very common and usually harmless, but they can be uncomfortable and may interfere with eating, drinking, and speaking.
What Causes Mouth Ulcers?
Mouth ulcers can develop for a variety of reasons. Often, the exact cause is unclear, but several common factors are known to increase the likelihood of an outbreak:
Physical Irritation
- Accidental cheek or tongue biting
- Irritation from dental braces, retainers, or poorly fitting dentures
- Minor injuries from dental procedures, such as fillings
- Abrasive or strongly flavored toothpaste and mouthwash
Dietary Triggers
- Eating acidic foods (e.g., citrus fruits, pineapples, strawberries)
- Consumption of salty or spicy foods that irritate the mouth lining
Allergic or Immune Reactions
- Sensitivity to certain bacteria naturally found in the mouth
- Allergic reactions to foods or oral care products
Lifestyle and Health Factors
- Hormonal changes, especially during menstruation
- High stress levels or emotional strain
- Lack of sleep or poor overall health
- Nutritional deficiencies, such as low iron or B-vitamins (in some cases)
Symptoms of Mouth Ulcers
Mouth ulcers are usually easy to identify due to their distinct appearance and discomfort. Common features include:
- Small, round or oval sores inside the mouth
- Red, inflamed borders surrounding the ulcer
- White, yellow, or gray center, which may look like a shallow crater
People may develop one sore or multiple ulcers at once. Additional symptoms can include:
- Swelling or puffiness around the affected area
- Sharp or burning pain, especially when eating spicy, salty, or acidic foods
- Discomfort while brushing teeth or talking
- Tenderness when touching the sore with the tongue
Management and Care
Most mouth ulcers heal on their own within 1–2 weeks. Helpful self-care measures include:
- Avoiding foods that irritate the sore
- Using a soft-bristled toothbrush
- Rinsing with mild saltwater
- Applying over-the-counter gels or protective pastes
Seek medical advice if ulcers are unusually large, very painful, occur frequently, or do not heal within two weeks, as these may indicate an underlying condition requiring further evaluation.
