What's Causing My Mouth Sores?Mouth sores, including canker sores, are a minor irritation that usually disappear after a week or two.
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Mouth sores are common ailments that affect about 80 percent of Americans at some point in their lives.
These sores can appear on any of the soft tissues of the mouth, including the lips, cheeks, gums, tongue, and floor and roof of the mouth. You can even develop mouth sores on your esophagus, the tube leading to the stomach.
Most commonly, mouth sores—which include canker sores—are a minor irritation and last only a week or two. In some cases, however, they can indicate mouth cancer or an infection, such as herpes simplex virus.
Herpes simplex causes cold sores, or fever blisters, and is highly contagious. The sores are contagious until completely healed, so be sure to wash your hands after touching them and to change your toothbrush once they are healed.
In most cases, mouth sores cause some redness and pain, especially when eating and drinking. Depending on the size, severity, and location of the sores in your mouth, they can make it difficult to eat, drink, swallow, talk, or breathe. The sores may also develop blisters.
Several things can lead to mouth sores, ranging from minor everyday causes to serious illnesses. Usually, a mouth sore might develop if you:
- bite your tongue, cheek, or lip
- burn your mouth
- have irritation from a sharp object, such braces, retainer, or dentures
- brush your teeth too hard, or use a very firm toothbrush
- chew tobacco
- are infected with the herpes simplex virus
Doctors do not know what causes canker sores. However, these sores are not contagious. You may be more prone to them due to the following:
- a weakened immune system because of illness or stress
- hormone changes
- a vitamin deficiency, especially of folate and B-12
- intestinal issues, such as Crohn’s disease or irritable bowel syndrome (IBS)
Occasionally, mouth sores are the result of, or a reaction to, the following:
- over-the-counter or prescription medications
- radiation or chemotherapy
- autoimmune disorders
- bleeding disorders
- bacterial, viral, or fungal infection
- weakened immune system due to AIDS or a recent organ transplant
You can usually tell when you have a mouth sore without needing a doctor’s diagnosis. However, you should see your doctor if you:
- have white patches on the sores
- have, or suspect you may have, herpes simplex or another infection
- have sores that do not go away after a couple of weeks, or they get worse
- just started taking a new medication
- started cancer treatment
- recently had transplant surgery
During your visit, your doctor will examine your mouth, tongue, and lips. If your doctor suspects you have cancer, he or she may perform a biopsy and run some tests.
Often, minor mouth sores often go away naturally within 10 to 14 days, but they can last up to six weeks. Some simple home remedies might help reduce the pain and possibly speed up the healing process. You may want to:
- avoid hot, spicy, salty, citrus-based, and high-sugar foods
- avoid tobacco and alcohol
- gargle with salt water
- eat ice, ice pops, sherbet, or other cold foods
- take anti-pain medications, such as acetaminophen
- avoid squeezing or picking at the sores or blisters
- apply a thin paste of baking soda and water
- gently dab on a solution that is one part hydrogen peroxide and one part water
- ask your pharmacist about other over-the-counter medications, pastes, or mouthwash that may be helpful
If you see your doctor for your mouth sores, he or she may prescribe a pain medication, anti-inflammatory drug, or steroid gel. If your mouth sores are a result of a virus, bacteria, or fungus, your doctor might provide a medication to treat the infection.
In cases of mouth cancer, a biopsy will be taken first. Afterward, you may need surgery or chemotherapy.
There is no absolute way to prevent all mouth sores. However, there are steps you can take to avoid getting them. You should try to:
- avoid very hot foods and drinks
- chew slowly
- use a soft toothbrush and practice regular dental hygiene
- see your dentist if any dental hardware or teeth may be irritating your mouth
- decrease stress
- eat a balanced diet
- reduce or eliminate food irritants, such as hot, spicy foods
- take vitamin supplements, especially B vitamins
- drink plenty of water
- do not smoke or use tobacco
- avoid or limit alcohol consumption
- shade your lips when in the sun or use SPF 15 lip balm
In most cases, mouth sores have no long-term effects.
If you have herpes simplex, the sores may reappear. Outbreaks are more common if you are under stress, if you are ill or have a weakened immune system, if you had too much sun exposure, or if there is a break in your mouth’s skin.
In cases of cancer, your long-term effects and outlook depends on the type, severity, and treatment of your cancer.
Edited by: Brittany Aubin
Medically Reviewed by: George Krucik, MD, MBA
Published: Sep 10, 2012
Last Updated: Feb 26, 2014
Published By: Healthline Networks, Inc.
- Mouth Sores (2011). National Institutes of Health. Retrieved July 5, 2012, from http://www.nlm.nih.gov/medlineplus/ency/article/003059.htm
- Canker Sores, Cold Sores, and Common Mouth Sores. American Dental Association. Retrieved July 5, 2012, from http://www.ada.org/2982.aspx
- Mouth Sores. (2010). American Academy of Otolaryngology - Head and Neck Surgery. Retrieved July 5, 2012, from http://www.entnet.org/HealthInformation/mouthSores.cfm
- Mouth Sores Caused by Cancer Treatment: How to Cope. (2011). Mayo Clinic. Retrieved July 5, 2012, from http://www.mayoclinic.com/health/mouth-sores/CA00054