The blue and painful side of the tongue may be caused by bad dietary habits, internal bruising, oral mucosal injury, etc. It can be treated by improving the diet, oral antiplatelet aggregation drugs, antiseptic and anti-inflammatory drugs. 1. Bad dietary habits: If the patient likes to eat spicy and stimulating food for a long time and does not pay attention to balanced nutrition, it may lead to the phenomenon that the side of the tongue is blue and painful. It can be relieved by improving diet, focusing on light and balanced nutrition. 2. Stagnant blood in the body: If there is stagnant blood in the body, resulting in slow blood flow and stagnation of blood in the local area, the symptoms of blue and pain on the side of the tongue may occur. Patients can be treated with oral antiplatelet aggregation drugs, such as aspirin enteric-coated tablets, clopidogrel bisulfate, etc., with caution for those who are allergic to the drug components or have severe liver damage. 3. Oral mucosal injury: oral ulcers are a common occurrence in the oral mucosa, ulcerative injury disease, oral ulcers may appear on the side of the tongue blue and painful phenomenon. Can be treated by oral antiseptic and anti-inflammatory drugs, such as roxithromycin capsules, metronidazole tablets, etc., allergic to drug components are prohibited, pregnant women, breastfeeding patients with caution. When the patient appeared the side of the tongue blue and pain, it is recommended to consult a doctor in a timely manner, identify the cause of the disease and follow the doctor’s instructions to use medication, do not use drugs, so as not to aggravate the condition.