Many different conditions can cause white spots on the tongue. Most of these conditions are of little or no medical concern, although they may be inconvenient or embarrassing. Factors such as drinking or smoking may disrupt the natural microbial balance in the mouth. A yeast infection can take root in the mouth and cause white spots on the tongue. Some potentially more serious conditions, including leukoplakia and syphilis, may cause whitening on the tongue as well.
The tongue and mouth are naturally filled with bacteria. These bacteria normally either have no impact on the body or are actually beneficial. Microorganisms in the mouth are typically kept in balance by other microbes and by the body’s natural defenses. When they are out of balance, however, they may build up in large numbers. These excess bacteria combine with detritus to form pasty white spots on the tongue, which can grow into a complete coating.
Some activities can upset the microbial balance in the mouth. Any activity that might kill large numbers of bacteria can do this. Bacteria not normally present in the mouth can then colonize the teeth and tongue and produce spots or a coating.
Drinking alcohol, especially distilled liquors, kills many bacteria in the mouth. Smoking can have a similar effect. Mouth breathing, either consciously or while sleeping, changes the environment of the mouth and can shift the microbial balance.
White spots can be caused by the growth of yeast as well. Candidia albicans yeast, the same yeast generally responsible for yeast infections, can infect the tongue. This is also known as oral thrush. Thrush, unlike simple bacteria overgrowth, can be somewhat painful. The white spots caused by yeast may bleed slightly as well.
Patients with compromised or undeveloped immune systems are at greater risk of infection. This includes the very young and the elderly. Individuals who wear false teeth are at an increased risk for thrush. The loss of most of the normal bacteria in the mouth, most often from antibiotic use, can also lead to the growth of oral thrush.
Leukoplakia, a condition that causes the normal skin cells in the mouth to grow too rapidly, can cause white spots. This condition is not serious in and of itself. It may eventually lead to cancer, however, and a doctor may order periodic tests to ensure that it does not.
Syphilis may also produce white spots on the tongue. This sexually transmitted infection is rare in the developed world, and easily treated with antibiotics. It can be dangerous if left untreated, however.