Numbness of the tongue when licking may be physiological factors, but also may be caused by burning mouth syndrome, lingual inflammation, lichen planus and so on. 1. Physiological: if you like to eat spicy and stimulating habitual food, or too hot diet, etc. can appear when the tongue licked numb phenomenon, change the dietary habits can be relieved. 2. Burning Mouth Syndrome: It is a common disease that occurs in the oral mucosa, the etiology of which is still unclear and may be related to peripheral nerve damage. Oral mucous membrane burning pain, dry mouth and other phenomena, may be manifested as a tongue licked numb phenomenon. 3. Tongue inflammation: it is an inflammatory reaction that occurs in the tongue, commonly caused by nutritional vitamin deficiency, such as vitamin B deficiency. Numbness and pain in the tongue can occur. 4. Lichen planus: it is a common skin disease that can involve the oral mucosa, the etiology of which is still unclear and may be related to genetic and infectious factors. The oral cavity can appear plaque and papule, accompanied by numbness. After the tongue is numb upon licking to exclude physiological factors, it is necessary to go to the hospital in time to avoid delaying the condition.