Blisters inside mouth

The lining of the cheek, lip, tongue, and palate can form a raised bubble or break into a sore. A clear bump after lip biting may behave differently from clusters of ulcers, a burn, a blood blister, or a lesion caused by a viral infection.

The dentist records the site, size, colour, texture, pain, recurrence, and duration, then checks nearby teeth and tissues. Persistent or unusual lesions may need a swab, blood test, referral, or biopsy to identify infection or tissue change.

Avoid bursting the area, biting it, or using irritant mouth products. Choose soft foods, keep the mouth clean, drink fluids, and note possible triggers such as sharp teeth, hot food, new products, illness, or medication.

Seek dental or medical assessment if a lesion lasts beyond two weeks, repeatedly returns, enlarges, bleeds, becomes hard, or is linked with fever, weight loss, or difficulty swallowing. Emergency care is appropriate for breathing difficulty or rapidly increasing swelling.

Ask what the lesion most resembles, whether a tooth or appliance is traumatising it, how long it should take to settle, and whether testing is needed.