Pain on one side of the tongue without visible ulcers may be due to lingual inflammation, glossopharyngeal neuralgia, burning mouth syndrome and other causes. 1. Inflammation of the tongue: refers to the inflammation of the special anatomical part of the dorsum of the tongue caused by lack of vitamins, anemia, infection and other reasons during the development of the tongue body. Due to the stimulation of inflammation, patients may experience symptoms such as numbness, burning pain, and pain when eating, i.e. the phenomenon of pain on one side of the tongue without obvious ulcers. 2. Hypoglossal neuralgia: an episodic severe pain in the distribution area of the hypoglossal nerve. Its etiology is still unclear, and it may be related to the short circuit of vagus nerve. Thus, patients can also appear on one side of the tongue pain without obvious ulcer phenomenon. 3. Burning mouth syndrome: it is a group of syndromes in which the tongue is the main site of development and burning pain is the main manifestation. May be due to dental calculus, oral bad habits, infection and other reasons, the patient can appear on the side of the tongue pain without obvious ulcer phenomenon. It is recommended that patients with pain on one side of the tongue without obvious ulcers go to the hospital in a timely manner, and follow the doctor’s instructions for treatment to avoid delaying the condition.