Glossitis is redness and swelling (inflammation) of the tongue. Possible causes of glossitis include an allergy or infection, an injury to the tongue, and nutritional deficiencies.

Although most cases of glossitis are minor and can be treated at home, symptoms can cause problems with chewing, swallowing, or speaking. Glossitis may also cause trouble breathing, if swelling is severe. If breathing difficulties develop, emergency medical care is required.