An oral ulcer or oral ulcer (synonyms: Aphthae; Aphthe; ICD-10-GM K13.-: Other diseases of the lip and oral mucosa) is a superficial injury to the oral mucosa (tunica mucosa oris) and the oral pharynx.
An oral ulcer can be a symptom of many diseases (see under “Differential diagnoses”).
The lifetime prevalence (disease incidence throughout life) is 70% of the population. These have oral ulcers either once or recurrently (recurring).
Course and prognosis: The course and prognosis depend on the cause of the disease. Often, oral ulcers heal spontaneously (on their own). If an oral ulcer persists after two weeks, medical evaluation is required.