My husband has got a white patch on his tongue. It is there from 2 months
White patch on the tongue can be due to various conditions / diseases. If your husband is tobacco addict (smoking or chewing), it can be leukoplakia, which is a precancerous lesion. Try to scrape this patch with a toothbrush, if it doesn't go it can be any precancerous lesion or precancerous condition (like leukoplakia, lichen plans etc.). If he doesn't have any oral habits, but his oral hygiene is poor (dirty teeth, swollen gums, foul mouth odor), than it can be a fungal infection called oral candidiasis. If the patch is non-itchy, you can rule out the fungal infection. Moreover, it can be a feature of HIV infection