The etiology of frequent long mouth ulcers is more complex, and there is no clear cause. Usually, there are several possibilities: 1. genetic factors, patients themselves carry ulcers and other pathogens, so the frequency of occurrence will be significantly higher than normal people; 2. systemic diseases, such as stomach ulcers, colitis, hepatitis or liver and gallbladder diseases, can produce ulcers; 3. environmental factors, such as living environment, psychological environment or social environment, such as lack of gold, copper, iron, selenium and other elements in food or vitamin Inadequate intake of vitamins and folic acid can easily lead to recurrent ulcers; 4. Infectious diseases, such as viral infections or bacterial infections can lead to ulcers; 5.