Things that can cause blisters to form on the gums include stress, poor dental health and hormone changes, according to the National Institute of Health. Other causes include lack of vitamins or minerals.
On rare occasions, disease and other medical conditions can cause blisters to form on the mouth. To relieve pain or discomfort associated with the blisters, patients should avoid hot food and drinks. They can also gargle will cool salt water several times per day. If the blisters lasts longer than 2 weeks, or a person experiences other troublesome symptoms, he should contact his doctor to find out the reason and receive treatment for the blisters.