Leukoplakia, oral thrush or candidiasis, oral lichen planus, or vitamin deficiencies can cause tongue lesions, according to WebMD. Lesions can also be the result of geographic tongue, scarlet fever or Kawasaki syndrome.
Other conditions that can lead to lesions on the tongue include biting the tongue or other traumas, smoking, and canker sores, according to WebMD. The papillae, or taste buds on the tongue can become inflamed and swollen. Oral cancer can also leave a sore or bump on the tongue. If lesions persist for more than two weeks, the person should see her doctor.
In leukoplakia, the cells of the mouth grow too rapidly, which results in white patches on the tongue, explains WebMD. This disease can increase a person's risk of cancer and often occurs in people who smoke. Thrush is a yeast infection that results in white, cottage-cheese like patches on the tongue.
Lichen planus presents as raised, lacy white lines on the tongue, says WebMD. Doctors are not sure what causes it, and it usually goes away on its own. Geographic tongue looks like a map of red spots on the tongue. The spots sometimes have white borders and tend to move around on the surface of the tongue.