8 Causes of a Mouth Ulcer

Mouth ulcers—also called canker sores—are small, painful sores, usually red or yellow, that can develop on the insides of the cheeks and lips, on the tongue and gums, or, rarely, on the roof of the mouth. Ulcers are most common in women and people under 45. Minor growths vary in size from about two to 8 millimeters and usually clear up within two weeks. Major ulcers are bigger and deeper, take several weeks to heal, and may leave a scar. There are many reasons a person may develop a mouth ulcer.

Stress or lack of sleep

One major cause of mouth ulcers is stress or lack of sleep, with an estimated average of 20% of adults who experience ulcers during stressful periods in their lives. One speculation as to why ulcers appear during these times is related to a drop in immunity which creates more vulnerability in the mouth.

Minor mouth injury

Minor mouth injury can be caused by many different things including dental work, poorly fitted dentures, braces, hard brushing, or accidentally biting your tongue or inside of your cheek. Anything that repeatedly rubs against the mouth and gums can cause an ulcer as well. Unfortunately, there is no quick fix to a minor mouth injury— it just needs some time to heal. Some things you can do to help relieve pain include:

Rinse mouth with warm water and salt or baking soda

Use milk of magnesia to the ulcer

Apply ice to the ulcer

Apply a damp tea bag to the ulcer

Use an over-the-counter oral topical anesthetic

Hormonal changes

Sometimes hormonal changes during puberty, menstruation, pregnancy, and menopause can cause mouth ulcers. This type of mouth ulcer can’t always be controlled or prevented, but you can take the necessary measures mentioned above to relieve pain and make it more comfortable.

Food sensitivities

Some people find that they get mouth ulcers after eating specific types of foods. One common type of food which may cause mouth ulcers includes citrus foods— like lemon, orange, or grapefruit—or other acidic foods, such as tomatoes, strawberries, pineapples, or even chocolate or coffee. The best way to avoid ulcers caused by food sensitivities is to identify which foods cause the ulcers, and to avoid eating them.

Deficiency in certain nutrients

Research shows that deficiency in certain essential vitamins and minerals especially in vitamin B12, folate, zinc, and iron, can cause mouth ulcers. If you have recurring mouth ulcers, you may want to visit your doctor to get checked for vitamin or mineral deficiencies. This can easily be done with a blood test, and if deficiencies are detected, you may be advised to take supplements.

Medications

Some medications may cause mouth ulcers—particularly non-steroidal anti-inflammatory drugs (NSAIDs), beta-blockers and painkillers. If you have been prescribed a new medication, or if you are taking NSAIDs to reduce inflammation and pain, and you develop mouth ulcers, you may want to talk to your doctor about switching medications.

Gastrointestinal tract problems

Inflammatory bowel diseases, such as Crohn’s disease or ulcerative colitis, can not only cause problems in the intestines but in the mouth as well. During flare-ups, mouth ulcers may appear or may worsen. This can happen for many reasons. Firstly, there is a connection between the inflammatory disease and between the immune system. When the immune system is weak, you are more likely to develop mouth ulcers. Secondly, patients who suffer from gastrointestinal problems are often deficient in essential vitamins and minerals because of lack of appetite, limitations on foods, and poor nutrient absorption. Lastly, patients with inflammatory bowel diseases may experience dehydration due to diarrheal symptoms of their disease. Dehydration is a slippery medical slope which can lead to many other symptoms, including mouth ulcers.

Bacterial, viral, or fungal infection

It is not common that a mouth ulcer is caused by an infection, although it does occasionally happen. One such infection may be herpes simplex.

Quitting smoking

About one-third of people who quit smoking develop mouth ulcers and cold symptoms within one or two weeks after quitting. This is one reason why so many people who quit are likely to have setbacks. Fortunately, the symptoms are temporary and usually resolve within six weeks of quitting. One reason why quitting smoking may cause mouth ulcers is because smoking possesses antibacterial properties, which causes the body to “forget” to produce antibodies in the mouth because it relies on the cigarettes to do the work for it. After quitting smoking, the mouth is more vulnerable because it doesn’t have those antibodies, but this usually works itself out because the body “remembers” to do it on its own within a few weeks. If you have an ulcer that lasts for more than three weeks, or you develop a fever or other flu-like symptoms, make an appointment with your GP.