Mouth Ulcers symptoms, causes and treatment

Mouth ulcers or canker sores are small but painful lesions or sores that form in the mouth or at the base of the gums. Mouth sores make talking, eating, and drinking uncomfortable, but they are usually harmless and clear up by themselves in a week or two.

Table of Medications


Mouth ulcers are quite common and can be managed at home, without having to see your doctor or dentist. 

Mouth ulcers are typically oval or round sores that appear inside the mouth on the cheeks, lips, and tongue. They can be red, white, grey, or yellow and may be swollen. Mouth ulcers may grow one at a time or may grow and spread.

Mouth ulcers are different from cold sores, which are small blisters that form around the mouth or the lips. Cold sores start with itching, tingling, or burning sensation around the mouth.

There are three types of mouth ulcers:

  • Minor ulcers are the most common among ulcers, which account for about 80% of ulcer cases. These ulcers are small, with a diameter of 2 to 8 mm, and heal naturally within two weeks. This type of ulcer will cause scarring.
  • Major ulcers are larger and deeper than minor ulcers. They usually have irregular or raised border. Major ulcers usually have a diameter of 1 cm or more. They take several weeks to heal and may cause scarring.
  • Herpetiform ulcers are multiple, pinhead-sized sores, numbering from five to 100. The tiny ulcers fuse to form irregular and larger sores, which could be very painful. About 10% of mouth ulcers are herpetiform. This type of ulcers has no relation to the herpes virus.

Mouth ulcers are common, with most people experiencing at least once during their lifetime. Mouth ulcers affect approximately 20% of the general population. These ulcers are more common in women than in men. They are also common in young adults.

Mouth ulcers are not transferred from person to person, even when one kisses someone with mouth ulcers.

Most people have mouth ulcers occasionally, although some have developed mouth ulcers on a frequent or recurring basis. In general, one out of five persons has recurring mouth ulcers. It is estimated that about 10% of children have recurring mouth ulcers. The factors causing recurrent mouth ulcers are different from those that cause single ulcers.

Causes of Mouth Ulcers

Most mouth ulcers are not caused by an infection. As such, mouth ulcers are not passed from one person to another.  Most minor ulcers are caused by damage to the mouth, such as when you accidentally bite the inside of your cheek while eating, using toothbrushes incorrectly, or from a sharp tooth or tooth filling.

The cause of recurrent mouth ulcers is not established, but many factors can increase your chances of getting recurrent ulcers, including:

  • Stress and anxiety
  • Oral trauma, such as chewing hard or sharp foods, or excessive tooth brushing.
  • Hormonal changes – Some women develop mouth ulcers while menstruating. This is due to the changes in the hormone levels during the menstrual cycle.

The consumption of certain foods may also increase your risk of developing mouth ulcers. The following foods are known to increase your risk of getting mouth ulcers:

  • Coffee
  • Chocolate
  • Almonds
  • Peanuts
  • Strawberries
  • Tomatoes
  • Cheese
  • Wheat flour

It is believed that recurrent mouth ulcers are hereditary because around 40% of people with mouth ulcers have a family history of the condition.

People develop more mouth ulcers than usual when they first stop smoking. This is a reaction of the body to the chemical changes that occur when quitting smoking. When you give up smoking, you will notice that there is an increase in your mouth sores, a temporary situation that should not discourage you from stopping smoking. Remember that the long-term health benefits of quitting smoking are greater than the short-term discomfort brought by mouth ulcers. When you stop smoking, you will significantly lower your risk of developing smoking-related conditions such as lung cancer and heart disease.

Underlying conditions

Recurrent mouth ulcers may be due to some underlying conditions, including:

  • Iron deficiency – A diet that lacks in iron means the red blood cells will be unable to carry as much oxygen, leaving you feeling lethargic, tired, and dizzy. Iron deficiency can cause mouth ulcers.
  • Vitamin B12 deficiency – This vitamin aids in making red blood cells and keeps the body’s nervous system healthy. A lack of this vitamin can result in shortness of breath, tiredness, and mouth ulcers.
  • Celiac disease – This condition is caused by an intolerance to gluten, a form of protein found in barley, wheat, and rye. The condition inflames the small intestine. Adults with celiac disease often have mouth ulcers.
  • Crohn’s disease – It is a condition that results in the inflammation of the gut, which leads to the development of ulcers in the stomach and mouth.
  • Reactive arthritis – It is a reaction of the body to another infection. It can cause inflammation that may spread to the mouth.
  • Immunodeficiency – This refers to a condition that suppresses or attacks the body’s immune system and may cause the person to develop mouth ulcers. 


Mouth ulcers may be caused by your body’s reaction to a medicine you are taking. Some of the medications that may cause mouth ulcers include:

  • Non-steroidal anti-inflammatory drugs or NSAIDs – They are medicines for pain. Children below the age of 16 should not take aspirin.
  • Beta-blockers – These medicines are used for the treatment of various conditions that affect blood flow and the heart, such as abnormal heart rhythms, angina, high blood pressure, and heart failure.

When you start taking any of these medications, you may notice the beginning of ulcers in your when. Mouth ulcers may appear also when you increase the dosage of these medicines.

Diagnosis and Treatment of Mouth Ulcers

Your doctor can diagnose mouth ulcers by conducting a visual exam. If you have recurring mouth ulcers, your doctor might test you for other medical conditions.


Most cases of mouth ulcers do not require treatment as they will go away on their own. But, if you have recurrent and painful mouth ulcers, several treatments can decrease the pain and the healing time. The treatments include:

  • Putting milk of magnesia on the mouth ulcer
  • Using a mouth rinse made of saltwater and baking soda
  • Covering your mouth ulcers with a paste of baking soda
  • Using topical anesthetic products like Anbesol and Orajel, which are over-the-counter products
  • Applying ice to the mouth ulcers
  • Using a mouth rinse that contains a steroid to reduce the swelling and pain
  • Placing damp tea bags on your mouth ulcer
  • Using topical pastes
  • Taking supplements such as Vitamin B-6, folic acid, vitamin B-12, and zinc
  • Trying some natural remedies including echinacea, chamomile tea, licorice root, and myrrh

Preventing mouth ulcers

Some steps may help reduce the occurrence of mouth ulcers. You should avoid foods that will irritate your mouth, including acidic fruits such as oranges, grapefruit, pineapple, and lemon, as well as chips, nuts, and spicy food. In place of these foods, choose alkaline fruits and vegetables, and whole grains. Eating a well-balanced diet and taking vitamin supplements will help you avoid mouth ulcers.

Accidental bites cause mouth ulcers. Avoid talking while you are chewing your food to prevent this accident. Maintaining good oral hygiene by regularly brushing and flossing will help. Avoid stress and get adequate rest and sleep. This will help you prevent many illnesses, including the problem of mouth ulcers.

Ask your dentist for a wax that can cover dental or orthodontic devices in the mouth that have sharp edges.

Risks of Having Mouth Ulcers

The risks of having mouth ulcers are high in people who smoke or use products that contain tobacco. Smokers who are also heavy drinkers of alcoholic products have a much higher risk of having mouth ulcers compared to the general population.

People who are infected with the human papillomavirus (HPV), that causes genital warts may also be at risk of having mouth ulcers.

When to Seek Medical Attention

People who frequently get mouth ulcers must make an appointment to see their doctor.

There are some instances when a person should see a doctor immediately, such as during:

  • the appearance of a non-painful ulcer in several areas of the mouth
  • ulcers that are spreading
  • unusual ulcers that appear in a new spot in the mouth
  • ulcers that last longer than 3 weeks

Some people may seek medical attention for their ulcers if:

  • they are particularly big or painful
  • the mouth ulcers are accompanied by a fever
  • the mouth ulcers develop after taking a new medicine
  • secondary bacterial infection.

Usually, mouth ulcers clear up on their own, and the pain that usually comes with the ulcer disappears in a matter of a few days. There are medications, either an ointment or solution, that may reduce the pain and swelling, but they are not necessary for the mouth ulcers to heal. 

Future outbreaks of mouth ulcers can be avoided by reducing stress and anxiety.

Table of Medications

  • triamcinolone
  • dexamethasone
  • Oralone
  • FIRST Mouthwash BLM
  • benzocaine
  • Orajel
  • Anbesol
  • Trianex
  • De-Sone LA
  • Pediaderm TA