Ulcers on the side of the tongue may be caused by recurrent aphthous ulcers, traumatic ulcers and so on, and can be treated in the oral mucosa department, as follows. 1. Recurrent Aphthous ulcers: the most common oral mucosal ulcer disease, the specific etiology is not clear, may be related to immune factors, genetic factors, systemic disease factors, infectious factors, environmental factors, etc., manifested as a central depression, pain obvious ulcers, the surface covered with yellow pseudomembrane, surrounded by a red halo band. 2. Traumatic ulcers: they are oral mucosal damages with clear etiology caused by physical, mechanical or chemical stimulation, such as long-term chronic stimulation of residual roots and crowns, accidental intake of caustic compounds such as strong acids and strong alkalis, and excessively hot food. It is recommended to visit a regular medical institution to receive professional targeted treatment.