Which factor is commonly associated with the occurrence of aphthous ulcers?

The occurrence of aphthous ulcers, also known as canker sores, is commonly associated with stress and illness. These painful lesions often appear on the mucous membranes of the mouth and can be triggered by various factors, with emotional and physical stress being significant contributors. Stress can weaken the immune system and decrease the body's ability to heal, making it easier for these ulcers to develop.

In addition, certain illnesses, particularly those that impact immune function or cause nutritional deficiencies (such as vitamin B12, folic acid, or iron deficiencies), can also be linked to the manifestation of aphthous ulcers. This connection highlights the importance of the body’s overall health and emotional state in the development of these oral lesions, making stress and illness key factors in their occurrence.