There are many reasons for cracks on the tongue, such as physiological factors, vitamin deficiency, inflammation of the tongue, psoriasis and so on. 1. Physiological factors: Cracks on the tongue may be due to congenital factors, which are usually related to chromosomal dominant inheritance. Secondly, some normal healthy people may have cracks on their tongues due to development, which is usually not accompanied by any discomfort and does not require treatment. 2. Lack of vitamins: daily picky about food, or anorexia, partiality, etc., will cause vitamin deficiency in the body, which may cause the phenomenon of cracks on the tongue. 3. Inflammation of the tongue: papillitis of the tongue can also appear on the tongue with cracks, and may also be accompanied by pain at the root of the tongue and other phenomena. 4. Psoriasis: Psoriasis is a chronic scaly skin disease caused by the interaction of many factors, which can cause the phenomenon of cracks on the tongue, accompanied by pain. There are many reasons for cracks on the tongue, if we exclude physiological factors, it is recommended to go to the hospital in a timely manner to improve the examination, follow the doctor’s instructions to take standardized treatment, do not ignore the symptoms, take it lightly.