Mouth Sores


Mouth sores are common ailments that affect many people at some point in their lives.

These sores can appear on any of the soft tissues of your mouth, including your lips, cheeks, gums, tongue, and floor and roof of your mouth. You can even develop mouth sores on your esophagus, the tube leading to your stomach.

Mouth sores, which include canker sores, are usually a minor irritation and last only a week or two. In some cases, however, they can indicate mouth cancer or an infection from a virus, such as herpes simplex.

If your mouth sore does not go away within 10 days, you should consult your dentist.

Conditions that cause mouth sores, with pictures:

Here are some of the more common soft-tissue disturbances:

Warning: Graphic images ahead.

Cold sores

Signs and symptoms of cold sores:

  • Cold sores, also called “fever blisters,” appear as clusters of red, raised blisters outside the mouth typically around the lips.
  • They are highly contagious and can break open, which allows the fluid in the blisters to leak out and spread the infection. 
  • They typically scab over until they heal.
  • They may also be accompanied by mild, flu-like symptoms such as low fever, body aches, and swollen lymph nodes.

Cause of cold sores:

Cold sores are caused by the herpes simplex virus (HSV)-1 and are highly contagious. There is no cure for the herpes virus. Reoccurrence can occur when an individual has a fever, menstruation, fatigue, stress, or exposure to the sun.

Treatment of cold sores:

Cold sore blisters usually heal by themselves in about one week. Over-the-counter topical anesthetics can provide some pain relief. Your dentist may prescribe antiviral drugs to reduce the healing time for these sores.

Canker Sores

Signs & Symptoms of Canker Sores

  • Canker sores often develop as small white or yellow center lesions with a red border.
  • They develop in the mouth on the tongue, inside cheek areas, lips, gum line, and throat area. 
  • They are not contagious. 
  • Canker sores may occur as one sore or several.

Cause of Canker Sores:

In some cases, the exact cause of a canker sore is unknown, but trauma or injury to the mouth or oral soft tissues may be the culprit. Other possible causes are food sensitivities, spicy, salty, or acidic foods, vitamin B deficiency, hormonal shifts, and stress.

Treatment of Canker Sores:

 These usually heal without treatment one or two weeks after they break out. However, if they are painful; so over-the-counter topical anesthetics and antimicrobial mouth rinses may provide temporary relief.

Read more about Tooth Pain Relief


Signs & Symptoms of Leukoplakia:

  • Leukoplakia is a white or gray area that develops on the tongue, inside of the cheek, or on the floor of the mouth. 
  • It’s commonly seen in smokers
  • Leukoplakia is usually harmless and often goes away on its own, but more serious cases may be linked to oral cancer
  • Regular dental care can help prevent recurrences
  • Leukoplakia is typically not painful or contagious.

Cause of Leukoplakia:

These can result from irritations that occur from fillings, crowns, or ill-fitting dentures.

Other causes include tobacco use, HIV/AIDS, and the Epstein-Barr virus. Sometimes, leukoplakia is associated with oral cancer, so it’s important to see your dentist if you notice any of these patches developing. Your dentist may recommend a biopsy if the patch appears suspicious.

Treatment of Leukoplakia

Treatment begins with identifying the source of the irritation. Once the irritant is removed, which may mean smoothing a rough tooth surface, repairing a dental appliance, or quitting tobacco use, the patches should disappear.

Tooth Abscess

A tooth abscess occurs when there is a bacterial infection in the nerve of the tooth. Symptoms of a tooth abscess include severe toothache with pain, sensitivity to hot and cold beverages or food, fever, and swollen lymph nodes.


This is a bacterial infection that occurs when there is an interruption of salvia flow from the salivary gland to the mouth. The gland is firm and can be painful with swelling in the area. If the infection spreads, one may experience fever, chills, and malaise.


Known as “thrush,” it is a fungal infection that occurs in the mouth or throat due to an overgrowth of yeast. Symptoms include white spots inside the mouth or on the tongue, sore throat, difficulty swallowing, and cracking at the corners of the mouth (cheilosis).

Can mouth sores be prevented?

There is no absolute way to prevent all mouth sores. However, you can take certain steps 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
  • don’t smoke or use tobacco
  • avoid or limit alcohol consumption
  • shade your lips when in the sun.

Are there any long-term effects of mouth sores?

In most cases, mouth sores have no long-term effects.

If you have herpes simplex, the sores may reappear. In some cases, severe cold sores can leave scarring.

While most sores and infections can be treated effectively, some are more serious and in rare instances could be a sign of oral cancer. Be on the lookout for a white or reddish patch inside the mouth, as well as a lump or thickening of the skin or mouth lining. Oral cancer can occur anywhere in the mouth, including the gums, lips, tongue, roof of the mouth, the floor of the mouth, and inside lining of the cheeks and the throat.


We love our patients and love to help them form healthy dental life that will last them a lifetime. For more information call us to answer all of your questions so get an appointment today.