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Canker sores are a common type of mouth ulcer. They are otherwise known as aphthous ulcers. Canker sores are painful, exposed sores in the mouth. They are often small and round. They are white or yellow and are surrounded by a bright red border.
Aphthous ulcers can develop on the inside of your cheek, under or on your tongue, on your lips, or in the back of your throat.
Canker sores are not the same as cold sores, otherwise known as fever blisters. Cold sores result from herpes simplex virus. They develop on the lips, gums and hard palate, and are contagious, which canker sores are not. A canker sore is not cancerous.
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In most cases, canker sores go away by themselves. However, there are over-the-counter (OTC) creams, ointments, mouthwashes, and rinses available that can help clear them up and reduce any pain. Painful sores can be relieved with over-the-counter medicines like ibuprofen.
Some home remedies can also help. Try mixing warm water with salt to make a mouth rinse to gargle. The salt water mouth rinse can help reduce the inflammation and pain of canker sores.
Avoiding hot and spicy foods when you have a canker sore helps. It would help if you also stayed away from acidic foods like citrus fruits like lemons and oranges.
If you experience major canker sores that are painful or persistent, speak to your doctor or health care provider for medical advice.
It’s still not known why some people develop canker sores, and others don’t. They are believed to be hereditary and are also influenced by many other factors. Canker sores can also link to problems with the body’s immune system.
Common causes of canker sores include:
Certain diseases can cause inflammations in the mouth that resemble canker sores. These medical conditions include chronic inflammatory bowel disease or Behçet's disease.
Mouth ulcers found on and under the tongue have many causes, including the ones listed above.
Common causes of canker sores on and under the tongue include:
Mouth sores on the gums can result from many causes.
Common causes of canker sores on the gums include:
Common causes of canker sores on or inside of the lips include:
While mouth sores usually develop inside the mouth or on the lips, they can sometimes form in the back of the throat and the tonsils.
Canker sores in the throat are often more challenging to treat. Applying a cream or gel directly onto mouth ulcers can be difficult. However, a medicated mouth rinse or wash can help clear up canker sores in the throat.
Mouth ulcers in the throat often result from something you ate or drank. This is because your tonsils come in contact with irritants when you swallow. A vitamin B12 deficiency can also lead to canker sores in the mouth and on the tonsils.
Common causes of canker sores in the throat include:
People experiencing recurrent canker sores often have a family history of the medical condition. This may be due to genetics or a shared factor in the environment, such as consuming certain foods or allergens.
Canker sores that persist may link to celiac disease, inflammatory bowel disease, or HIV/AIDS.
Children and teens often develop canker sores between the ages of ten and 19. Around three in ten children experience mouth ulcers. Canker sores cannot spread from one child to another.
Common causes of canker sores in kids include:
Canker sore, MedlinePlus, 2020, https://medlineplus.gov/ency/article/000998.htm
Canker sores, MedlinePlus, 2019, https://medlineplus.gov/cankersores.html
Dalessandri, D., Zotti, F., Laffranchi, L. et al. Treatment of recurrent aphthous stomatitis (RAS; aphthae; canker sores) with a barrier forming mouth rinse or topical gel formulation containing hyaluronic acid: a retrospective clinical study. BMC Oral Health 19, 153, 2019, https://bmcoralhealth.biomedcentral.com/articles/10.1186/s12903-019-0850-1
Canker sores (mouth ulcers): Overview., InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG);2019 Aug 15, https://www.ncbi.nlm.nih.gov/books/NBK546250/
Canker Sores (Aphthous Ulcers) in Children, University of Rochester Medical Center, https://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=90&ContentID=P01843