What are the Mouth Ulcers
Mouth ulcers are one of the most prevalent types of sores in the oral cavity, commonly emerging on the inner lips, tongue, cheek lining, or along the gum edges. They range in size and often cause discomfort, yet the majority heal spontaneously without treatment. Approximately 20 % of individuals experience recurrent (aphthous) ulcers; those that persist or recur may warrant medical attention, as they can signal an underlying condition. These sores are non-contagious and are also known as canker sores.
Types of mouth ulcers3,4
- Minor ulcers measure 2–8 mm, usually heal within two weeks, and cause mild discomfort.
- Major ulcers exceed 8 mm, often present as deep, raised, irregular lesions, can take up to six weeks to resolve, and may scar.
- Herpetiform ulcers occur in clusters of 10–100 tiny, pinpoint sores resembling herpes lesions but are not infectious. They typically arise in adults and clear within weeks without scarring.
Symptoms of mouth ulcers
Pain during eating, drinking, or tooth brushing is common and may worsen with poor oral hygiene. The appearance varies by ulcer type:
- Minor and major ulcers: one or more round lesions with red borders and yellow, grey, or white centers on the cheeks, palate, gums, or tongue; severe cases may bring fever, fatigue, or swollen glands.
- Herpetiform ulcers: extremely painful, frequently recur or merge into larger ulcers, and may take longer than ten days to heal.
Causes of the mouth ulcers
While no single cause exists, several factors can trigger ulcers:
- Accidental cheek bites or mouth injuries (e.g. from brushing, braces, or sharp teeth)
- Burns from hot foods
- Spicy or acidic foods
- Sensitivity to toothpaste or mouthwash
- Certain medications (e.g. pain relievers, beta-blockers)
- Deficiencies in vitamins B-12, folate, iron, or zinc
- Hormonal changes (puberty, pregnancy, menopause)
- Stress, anxiety, or severe fatigue
- Oral skin conditions (e.g. lichen planus)
- Other bacterial, fungal, or viral infections (including cold sores)
Ulcers can also indicate systemic disorders such as coeliac disease, Crohn’s disease, inflammatory bowel disease, HIV/AIDS, diabetes, Behçet’s disease, or even oral cancer.
Complications of mouth ulcers
While most mouth ulcers resolve without issue, some may scar, become infected with bacteria, or even elevate the chance of developing oral cancer.
Treatment and Healing
Typically, ulcers self-heal within 10–14 days and require no intervention, though OTC pain relievers or an anaesthetic mouth gel can ease discomfort. Your pharmacist can recommend suitable products. Persistent or herpes-related ulcers might need a topical mouthwash, ointment, or gel, and in severe cases, immunosuppressants may be prescribed.
Self-Care Tips12,13
- Avoid touching the sore; if you must, wash your hands before and after.
- Use a soft toothbrush or rinse with mouthwash if brushing is painful.
- Rinse with salt water (1 teaspoon in 1 cup), hold for 2 minutes, then spit out, repeat several times daily.
- Choose soft foods and steer clear of acidic or spicy items.
- Drink through a straw and sip cool water to soothe pain.
- Take OTC pain medication as needed.
When to See a Doctor14
Consult a physician if ulcers last longer than two weeks or significantly disrupt eating, drinking, or daily life, and particularly if you notice any of the following:
- Sores extending onto the lips
- Unusually large or painless ulcers
- Pain that OTC medications cannot control
- New ulcers forming before old ones heal
- Difficulty eating or drinking
- Weight loss, high fever, or diarrhea