Red tongue, there may be the following reasons: 1, taking some food with red pigment, exogenous substances with pigment can be deposited on the surface of the tongue, and the tongue can be stained. If you eat drugs or foods that contain red color, you can make your tongue red, for example, if you eat red dragon fruit, your tongue can become red.2. Atrophic ligamentitis can occur with atrophy of the tongue moss, which makes the tongue red, and anemia, niacin deficiency, dry syndrome, and Candida albicans infections may be related.3. Burning of the mouth, in the case of burning of the mouth, there is a possibility that the tongue moss may undergo atrophy, which makes the tongue become red. The tongue may become reddish. So if you have a red tongue, you can brush your teeth and rinse your mouth to see if you can remove the red color. If the red color cannot be removed, you can go to the stomatology department of a regular hospital.