There are many reasons for recurrent mouth ulcers, with the most common causes being immunologic, psychosomatic factors, and dietary habits. Recurrent mouth ulcers are often referred to as recurrent mouth ulcers, generally with individual variability, the causes are mainly seen in the following aspects: 1. Immune factors: people with poor immune function will have a higher chance of getting mouth ulcers than ordinary people. 2. Psychological factors: people who are often anxious and sleep deprived have a higher chance of getting mouth ulcers, which are also prone to recurrence. 3. Dietary habits: often eat spicy and stimulating food or partiality, can lead to the recurrence of mouth ulcers. There may be other reasons for the recurrence of mouth ulcers, such as heredity, systemic diseases, etc. It is recommended to consult a doctor in time, complete the relevant examinations, and carry out targeted treatment and therapy after the cause of the disease has been clarified.