Canker sore

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at January 22, 2016
StartDiseasesCanker sore

A canker sore is a small lesion that invades the mouth and sometimes causes minor pain or discomfort. Most are known as simple canker sores and occur between the ages of 10 to 20 and are not severe at all. The rare form is known as complex canker sores.


Definition & Facts

Those who suffer from simple canker sores will usually experience them just a few times annually. The discomfort and pain is usually not severe. They are present on the mouth, the tongue or on the inside of the cheek. They are usually yellowish or white and surrounded by red tissue. They are not contagious and usually will fade within a few weeks.

Patients who experience severe canker sores characterized by excruciating pain, overwhelming outbreaks and the inability to swallow usually opt to contact a doctor. However, the majority of canker sore cases are extremely mild.

Symptoms and Complaints

The symptoms of simple canker sores are fairly easy to identify. If an individual experiences tingling on their tongue, they may be in the process of developing a canker sore. A few days later, they will experience painful sores inside of their mouth. This includes the tongue, the inside of the lip and the inside of the cheek. If they look in the mirror, they may see yellowish and white sores surrounded by inflamed tissue of their mouth.

However, if somebody is suffering from complex canker sores, the symptoms will be more extreme. They will experience a high fever, fatigue, and swollen lymph nodes. All of these warrant contacting a physician to allow them to examine the patient's complex canker sores and to decide the appropriate course of action.


Though medical professionals are not totally sure about what causes canker sores, they have developed a few reasonable hypotheses. Doctors think that the following could be potential culprits.

  • Stress
  • Certain foods such as citrus
  • Dental applications. Sharp surfaces such as braces are sometimes thought to bring about canker sores
  • Vitamin deficiency
  • Underlying medical problems, such as a poor immune system. If an individual's body is less likely to ward off infections, they will be more vulnerable to outbreaks of lesions

Diagnosis & Tests

A trained physician should be able to identify a canker sore by sight. However, there are certain details that may lead the physician to think that it is not a canker sore. If has been three weeks and still has not healed, this may be cause for concern. If the patient were very concerned with the identity of the canker sore, he or she could have the physician run some blood tests to confirm that it is not something worse. If the doctor is led to think that it is a virus or hormonal deficiency, the doctor will take a blood test to make this decision.

Further, if there is a severe breakout, the physician will likewise take a blood test. A severe breakout of canker sores could be indicative of something worse, such as an immune deficiency. This will also serve as an indicator of complex canker sores. This can be diagnosed with the outbreak of lesions and the accompanying symptoms, such as a fever, fatigue, and swollen lymph nodes.

Treatment & Therapy

Patients do not usually think treatment for canker sores is necessary. The discomfort and pain is mild and not warranting any action. They will usually go away on their own in just a matter of a few days. However, if a canker sore is large and painful, the health care provider may prescribe antimicrobial mouth rinse or even pharmaceutical drugs depending on the severity of the pain.

Patients have also found success applying a cotton swab dampened by a mixture of hydrogen peroxide and water three times every day until the lesions begin to fade. Second, some have reported that regular gargling with saltwater has reduced the pain. While this may be rather uncomfortable the first time one does it, patients report that it reduces their pain. Third, some have applied milk of magnesia three times every day to reduce the pain.

Prevention & Prophylaxis

There are a number of preventative measures that physicians have recommended. Food that irritates the mouth should be avoided. This would include anything spicy or sour. Similarly, chewing gum could trigger a canker sore. Finally and most prominently, patients who regularly brush their teeth are much less likely to develop canker sores. It will enhance overall oral health and will cleanse the mouth of residual foods that might contribute to canker sores.