Discomfort: Tongue discomfort can result from irritation by certain foods, especially acidic ones (for example, pineapple), or by certain ingredients in toothpaste, mouthwash, candy, or gum. Some drugs can cause tongue discomfort, as can injury and infection. A common infection causing tongue discomfort is thrush (candidiasis), in which an overgrowth of fungi forms a white film that covers the tongue. Intense pain of the entire mouth can be caused by burning mouth syndrome.
Usually, it is a process of elimination to find out just what is causing the discomfort. Tongue discomfort not caused by an infection is usually treated by eliminating the cause. For example, the person may try changing brands of toothpaste, discontinue irritating foods, or have a sharp or broken tooth repaired by a dentist. Warm salt-water rinses may help.