Canker sores are small, shallow sores that develop on the soft tissue inside the mouth or the gums. Unlike cold sores, canker sores are not contagious and do not appear on the outside of the mouth or the lips. There are many causes of canker sores, from emotional stress to food sensitivities. While most canker sores naturally go away on their own after one or two weeks, they can be incredibly painful and make it difficult to speak and eat.

1. Overzealous Brushing

According to many dentists, if you are squashing the bristles of your toothbrush while brushing your teeth, you are brushing too hard. The gums and soft tissue of your mouth are very sensitive. Vigorous brushing can cause small tears or inflammation in the tissues. These minor injuries are the most common precursors to canker sores. When brushing your teeth and gums, apply only enough pressure that you feel the bristles lightly against your mouth.

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