Oral health is a key component of overall well-being. Taking care of your mouth doesn’t just mean having clean teeth and a bright smile—it also means protecting your body from infections and inflammation that can have significant effects on your health.

Among the most common and bothersome oral issues are canker sores—small ulcers that, despite their size, can greatly affect daily life. These painful lesions develop on the soft tissues inside the mouth, particularly on the tongue, the inner cheeks, the gums, or the soft palate.

While not contagious, they are generally quite uncomfortable and can make basic activities like eating or speaking difficult. Canker sores, also known as aphthous ulcers, have a typical appearance: small, roundish erosions with a whitish or yellowish center surrounded by a red halo. Unlike viral infections like herpes, they don’t spread from person to person and don’t affect the outside of the lips—they occur exclusively inside the mouth.

There are many interconnected causes that contribute to their appearance. According to the Italian National Institute of Health and the Ministry of Health, there is no single explanation for the development of canker sores, but several factors appear to play a role.

These include both physical and emotional stress, and minor local trauma—such as aggressive brushing, accidentally biting the inside of the cheek, a scratch from a chipped or sharp tooth, or an ill-fitting dental prosthesis. Nutritional deficiencies, particularly in vitamins, can also weaken the oral mucosa and make it more susceptible to ulcers.

Other possible triggers include immune system imbalances, as well as intolerances or sensitivities to certain foods—such as chocolate, citrus fruits, spicy or acidic foods. In some cases, the appearance of canker sores may also be linked to hormonal imbalances.

In most cases, canker sores heal on their own within a week to ten days. During this time, even though healing occurs naturally, it’s helpful to manage the pain by avoiding acidic or salty foods and other irritants. Applying specific products like gels, mouthwashes, or anti-inflammatory and anesthetic agents can help speed up recovery. It’s also important to maintain proper oral hygiene and try to reduce stress as much as possible.

However, it’s important to pay attention when canker sores become unusually large, painful, or frequent. If the lesions don’t heal within two weeks, or if they appear alongside other symptoms such as fever, joint pain, or gastrointestinal issues, it’s strongly recommended to seek medical attention. In these cases, consulting a specialist can help rule out more serious conditions and determine if further diagnostic tests are needed.

Though generally harmless and self-limiting, canker sores deserve attention when they become persistent or disruptive. Taking care of your oral health and not ignoring unusual signs is the first step toward protecting your overall well-being.