Dear Ma am, Hi & Welcome to HCM. I appreciate your concern for the noticeable blood vessels under the tongue. Most likely this condition is of no great concern. This may be functional and harmless and can be noticed if your BP is high. Please make sure to monitor your BP and rule out high blood pressure that requires medical attention. Thus you need to be examined by a dentist and physician to rule out vascular malformation, deposits on vessels restricting blood flow, tumor, vitamin deficiencies or imbalances. Do you have any habits that may contribute to this reaction in so far as being an irritant? Avoid irritants such as smoking, alcohol and acidic foods as well. Stay well hydrated. Hope to have answered your query. Best regards.