Bruising at the base of the tongue may be a physiological phenomenon, or it may be caused by cysts of the sublingual gland, myocardial ischemia, and so on. Physiological phenomenon does not need to be dealt with, while those caused by diseases need to be eliminated by medication or surgery according to the cause. 1. Physiological phenomenon: There are normal physiological structures under the tongue such as veins and blood vessels, sublingual caruncles, etc. Some people have these structures looking more obvious and may have the appearance of bruises at the bottom of the tongue. This is usually a normal physiological phenomenon and does not require special treatment to eliminate. 2. Sublingual gland cysts: Sublingual gland cysts are caused by the blockage of the duct of the sublingual gland, which may affect the blood circulation under the tongue, resulting in blood circulation failure and causing blackening of the tongue. This condition usually requires surgical removal of the sublingual gland cysts to alleviate the blood circulation obstruction so as to achieve the therapeutic effect. 3. Myocardial ischemia: When patients suffer from myocardial ischemia, the failure of systemic circulation can lead to poor blood circulation under the tongue, which can lead to more obvious blue veins at the base of the tongue. Atorvastatin, isosorbide nitrate and other drugs can be used for treatment under the guidance of a doctor. After excluding physiological reasons, it is recommended to go to the regular hospital for examination in time.