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Of all the different types of mouth sores, canker sores might be the most mysterious. It isn’t well understood why people get them. Canker sores develop on the inside of the mouth, cheeks and lips and on the tongue and gums. Although they aren’t contagious, the tingling pain can be unpleasant. If you have a canker sore, stress or anxiety could be a potential influence.

If you think your canker sores are connected to stress levels, learning to recognize and manage your triggers might help you avoid a flare-up.

Understanding the Causes of Canker Sores

Although the specific cause of canker sores isn’t known, dentists and doctors have noticed a few risk factors. For example, the U.S. Office on Women’s Health points out that women tend to get canker sores more than men, so your biology may come into play. An injury inside the mouth, such as from biting the inside of your cheek or lip, may also increase your risk of developing a canker sore, as can emotional factors like stress and fatigue.

A few small studies have taken a look at the role anxiety and depression play in the development of canker sores or recurrent aphthous stomatitis (RAS), which are canker sores that form often. The Merck Manual estimates that RAS occurs in 20 to 30 per cent of adults.

One study, published in the Journal of Oral Pathology and Medicine, evaluated the role of anxiety, psychological stress and depression on RAS. After giving participants a series of questionnaires and psychological tests, the researchers determined that there appeared to be a link between canker sore stress, depression and anxiety and the symptoms of this oral problem.

A second study, published in Contemporary Clinical Dentistry, evaluated the psychological profiles and salivary cortisol levels (which can indicate stress) of people with RAS. Although the study was small, researchers were able to draw the conclusion that levels of anxiety and depression were higher in people with RAS than in the control group.

How Stress Affects Canker Sores

How stress can cause canker sores isn’t well understood. One hypothesis, stated in a paper published in the Journal of Oral and Maxillofacial Pathology, is that people are more likely to bite their cheeks or lips when anxious or stressed, causing trauma to the mouth that can make canker sores likely to develop. The same paper notes other studies that suggest that stress is a trigger for canker sores, rather than a direct cause of them.

How to Reduce Canker Sores Under Stress

If you’ve noticed that stress or anxiety seems to trigger canker sores for you, learning how to manage your stress might help you avoid a flare-up. Managing stress can also have other benefits for your oral health, as there is a potential link between stress and gum disease.

There are a few ways you can reduce stress. Taking deep breaths when you are in a tense situation can help calm you. Practising meditation can also help you feel more at ease. If your stress levels are consistently high, you might need to make larger changes, such as cutting back on your workload or getting more help at home. Always consult a medical professional before making any major lifestyle changes or if you feel overwhelmed.

While canker sores are usually little more than a nuisance, it’s a good idea to call your dentist if you find yourself getting them frequently or if they are larger than a centimetre. Your dentist can recommend treatments to ease the discomfort caused by the sores and help you get to the bottom of what’s causing them. Keep up your daily oral hygiene habits and consider adding a mouthwash to your routine.