Tongue can show different varieties of lesions,both red lesions, white lesions, there will be some black pigments on the tongue. So some of them are normalvariations and some could be injurious later. So most commonly what we see is candidiasis, mostly we see in HIV patients and immune compromised patients. There is something called leukoplakia, again a white lesion on the tongue which is most commonly seen in patients having smoking habit. Chronic smokers there are other lesions like lichen pla