Do You Have the Symptoms of a Canker Sore? (2024)

Canker sores, also known as aphthous ulcers or recurring aphthous stomatitis, are small pitted lesions (sores) that occur inside the mouth. There are three types of canker sores that can be uncomfortable and make it difficult to eat or even talk.

Roughly 20% of people will develop canker sores at some time in their life, though their exact cause is unknown. They are not contagious and most canker sores do not need to be treated by a healthcare provider. However, you may want to seek treatment for sores that fail to heal after 14 days.

This article discusses the symptoms and treatment of three types of canker sores—including their appearance and who may be at risk. It presents possible causes of canker sores and ways to tell them apart from other types of mouth sores.

Types of Canker Sores

Not all canker sores are alike. Canker sores all occur in the mouth, but they may be classified as minor, major, or herpetiform.

Men and women tend to be equally affected, although women appear to have a slightly greater risk of herpetiform sores. Bacterial changes may play a role in developing the sores. An underlying disease (like digestive illness) or medication use (as with nonsteroidal anti-inflammatory drugs, or NSAIDs) are among factors that can increase your risk.

Minor or Simple

Minor canker sores are the most common type accounting for around 80% of cases. The size can vary, but they are typically between 1/3 inch and 1/2 inch. They are also sometimes referred to as simple canker sores.

Although painful, minor canker sores are often fully healed within two weeks. They can occur spontaneously, often after a minor mouth injury (from a spicy food, for example) or during times when you are chronically overworked, stressed, and exhausted.

Other causes can include:

• Irritation from braces or dentures
• Accidentally biting your cheek
• Burning your mouth from hot food or drink
• Smokeless tobacco use

Major or Complex

Major canker sores are larger than 1/2 inch and tend to last for up to six weeks. In many cases, these sores begin in adolescence and become a chronic, lifelong condition. These account for 10% of canker sores.

Where minor canker sores are typically round and symmetrical, major canker sores often have irregular, oddly-shaped borders. On rare occasions, this type of canker sore can leave behind a scar.

Major canker sores may also be referred to as complex canker sores. Their causes can include:

• Vitamin deficiencies
• Chemotherapy treatments for cancer
• Viral infections (like HIV, which leads to a weakened immune system)
• Genetic factors

Herpetiform Canker Sores

Herpetiform canker sores are a cluster of several tiny lesions that often converge to form one large sore. Hundreds of pinhead-sized lesions can be involved. Herpetiform canker sores may last from one week to one month.

These canker sores can look like a herpes outbreak, but the herpes virus is not involved. The cause is unknown but they tend to occur later in life.

Herpetiform canker sores represent 5% of aphthous ulcer diagnoses and tend to affect younger adults. These sores are often diagnosed in people with a SARS-CoV-2 (COVID-19) infection, but studies have yet to establish exactly why.

Canker Sore Symptoms

Canker sores appear inside of the mouth as round or oval sores typically with a raised border and a yellow, gray, or white center. They typically develop:

• On the top surface of the tongue and the tip of the tongue
• Underneath the tongue and on the floor of the mouth
• On the inside of the cheek or lip
• On the gum tissue

One to two days before the appearance of the lesion, there may be a localized burning or tingling sensation inside the mouth.

Canker sores can become quite painful, especially when eating, drinking, and talking.

When to See a Healthcare Provider

You should see a healthcare provider for your mouth sores if they have not healed and last more than two weeks. Other reasons to see a healthcare provider include:

• A sore or sores that started soon after you began a new medication
• Sores that may be something else and need a diagnosis, such as large white patches on the roof of your mouth typically associated with thrush (oral candidiasis)
• A history of cancer, HIV, or other illnesses that can weaken your immune system

If you have more severe symptoms of fever, skin rash, swollen lymph nodes, or trouble swallowing along with your sores, contact your healthcare provider.

Causes

While the of causes canker sores are unknown, along with previously discussed factors, underlying health conditions that may increase your risk can include:

• Behcet's disease, a rare autoimmune disorder with oral symptoms
• Hormonal changes during menstruation
• Celiac disease
• Inflammatory bowel disease (IBD)
  
• Helicobacter pylori (the bacteria that causes peptic ulcers)

Treatment

Canker sores do not necessarily need to be treated. If they do, they may respond to at-home remedies like a saltwater-and-sodium-bicarbonate mouth rinse.

Home Remedies to Try

Mix half water with half hydrogen peroxide, and use a cotton swab to apply it to the sore. Then put a small amount of Milk of Magnesia on it, repeating these steps three to four times a day.

Or, you can mix Milk of Magnesia and Benadryl liquid in equal parts. Swish the mixture in the mouth for about one minute and then spit out.

Medications

Over-the-counter options include topical numbing agents like Anbesol (benzocaine). When severe, prescription drugs may be needed. These include topical steroids like Lidex (fluocinonide), antacids like Carafate (sucralfate), or oral steroids like Decadron (dexamethasone).

If your canker sore is large and painful, your healthcare provider may prescribe an antibacterial mouth rinse or a corticosteroid ointment. Over-the-counter oral pain gels are also available to help ease symptoms.

Canker Sore Prevention

One of the best ways to avoid canker sores is to treat the underlying cause, and your healthcare provider can help you with a diagnosis.

For example, improperly fitting dentures or broken teeth should be repaired. Dietary changes may help if you have celiac disease or IBD or tend to get sores after eating certain foods. They also can help to address any vitamin deficiencies that may be part of the problem.

Stress management techniques may also help as stress can lead to canker sores in some people.

Summary

Canker sores, also known as aphthous ulcers, are painful, pitted sores inside the mouth. There are three different types: minor canker sores (the most common type), major canker sores (often seen in immunosuppressed people), and herpetiform canker sores (which cause clusters of pinhead-sized lesions).

Although the cause of canker sores is poorly understood, they are linked to stress, mouth injuries, food sensitivities, vitamin deficiency, menstruation, digestive disorders, and impaired immunity. Canker sores don't always need to be treated, but some may benefit from a topical numbing agent, antiseptic mouthwash, changes in diets, or oral or topical steroids.