What Causes Blisters in the Mouth?
Several different things can cause blisters inside the mouth:
Tissue Trauma or Irritation. If you have a broken filling or sharp tooth, they can very easily cut into your mouth tissue, causing you to have a blister. Similarly, poorly fitted dentures or braces can cause a similar problem. A study in Trauma in Dentistry also notes that chronic biting of your cheeks or lips can cause lesions. Accidental biting of your lip or cheek might also cause a mouth blister.
Tissue Burn. The Trauma in Dentistry study points out that thermal burns in the mouth are highly prevalent amongst children and young patients. They’re caused by accidentally ingesting a hot liquid or food, resulting in blisters around the burnt area. While tissue burns aren’t usually severe, you should not contaminate the blisters while they heal.
Cold Sores. These are caused by the herpes simplex virus and are very contagious. Often, you’ll experience tenderness or a burning sensation before the actual sore appears. They will begin as blisters and then crust over. While the herpes virus can live in your body for years, it only appears as sores when it’s triggered by something else, such as stress, sun exposure, another illness, or hormonal changes like menstruation.
Canker Sores. Unlike cold sores, canker sores aren’t contagious. They can look like a pale or yellow ulcer appearing in your mouth with a red outer ring. You may see one or several of them. Unfortunately, we don't know the exact cause of canker sores. Still, they have several risk factors and triggers, including hormone changes, stress, a weakness in your immune system, or a lack of certain vitamins and minerals in your diet.
MedlinePlus also notes that while it’s less common, blisters in the mouth can also be a sign of:
- Autoimmune disorders
- Cancer of the mouth
- Hand-foot-mouth disease
- A weakened immune system caused by a disease like AIDS or if you’re taking medicine after a transplant