A sore mouth can be caused by a systemic illness, a local infection, an allergic reaction, an irritant or improperly fitted dentures, according to Merck Manuals. It can also result from chewing tobacco, wearing braces and trauma to the mouth, such as accidental bites and burns, states WebMD.
Mouth sores can range from a single ulceration to severe widespread inflammation in the oral mucosa, states Merck Manuals. Mouth sores are generally painful and can cause disruption in a person’s eating and sleeping habits, occasionally resulting in malnutrition and dehydration.
A sore mouth can be a symptom of a systemic disorder, such as leukemia and celiac disease, explains Merck Manuals. Mouth inflammation can also be a sign of certain bleeding and autoimmune diseases, including Behcet syndrome and Kawasaki disease. A bacterial, fungal or viral infection can also cause mouth sores.
Mouth sores can also result from hormonal changes and a weakened immune system, explains MedlinePlus. Stress and sun exposure, as well as vitamin and mineral deficiencies, are other possible causes of mouth sores.
Hypersensitivity to some medications and foods may also lead to mouth sores, states WebMD. Patients undergoing chemotherapy and radiation therapy have the tendency to develop mouth sores as well. Certain drugs, such as antibiotics, barbiturates and anticonvulsants, may also cause mouth inflammation, according to Merck Manuals.