White tongue may be caused by Candida infection, oral leukoplakia, leukokeratosis and other diseases. 1. Candida infection: Candida infection is a fungal infection, which is manifested by white velvety patches on the tongue, which can be wiped off by exertion. It can be treated with ketoconazole and fluconazole under the guidance of physicians. 2. Oral leukoplakia: mostly white or grayish-white plaque, patients can feel the tongue slightly rough, astringent symptoms, commonly found in the smoking population. Patients can use vitamin A, cod liver oil and other treatment under the guidance of physicians, and should pay attention to quit smoking and alcohol. 3. White keratosis: it can be manifested as white patches or plaques with unclear boundary on the tongue, which is generally caused by long-term mechanical stimulation or chemical stimulation, and can be treated with vitamin A acid, vitamin E and other medicines under the guidance of professional physicians, and requires timely consultation and treatment. When there is a persistent white tongue, you should consult a doctor in time, after a clear diagnosis and active treatment.