Tongue ulcers under the skin of the mouth numbness may be bad habits, lack of vitamins, viral infections and other reasons. 1. bad habits: if the patient has long-term smoking, like spicy stimulating food, do not pay attention to oral hygiene and other bad habits, there may be a long tongue ulcer under the skin of the mouth numbness of the situation. 2. lack of vitamins: vitamins are essential nutrients, if the lack of human metabolism will have an impact on all aspects of the human body, seriously affecting the normal physiological function, so the lack of vitamins may also lead to patients with tongue ulcers under the numbness of the skin of the mouth symptoms. 3. Viral infections: viral infections mostly occur in the lack of immunity to the virus in the population, so when the patient is under stress, physical fatigue or lack of energy, the virus will attack, and thus there is a possibility of tongue ulcers under the numbness of the skin of the mouth phenomenon. When the patient has the symptoms of tongue ulcers under the skin of the mouth numbness, it is recommended to go to the regular dental hospital in a timely manner to identify the cause of the disease, under the guidance of the doctor active treatment.