Thrush, an infection that occurs on the tongue and inside the mouth, is caused by the yeast Candida. When Candida is present inside the mouth in small numbers, it does not cause any issues, but if it grows beyond those small numbers, it may attack the surrounding mucous membranes and cause an infection. Those with weakened immune systems are at the highest risk of infection. The most common form of thrush-causing yeast is Candida albicans, but other causes of thrush may include Candida tropicalis, Candida glabrata, Candida parapsilosis, and Candida krusei.
Thrush can be found inside the mouths of people at any age, although it is most common in babies. It is usually diagnosed by telltale patches of white on the tongue and in the mouth. Usually, naturally occurring bacteria inside the mouth control the growth of the yeast, but sometimes new bacteria will be introduced to the mouth that pushes the yeast that causes thrush into an overgrowth.
The causes of thrush may vary depending on a person’s general health. For example, one of the causes of thrush is an inability to ward off an infection. Most people with a strong immune system are able to prevent the thrush-causing yeast from growing too rapidly. If the immune system is weak, the yeast may grow too fast and cause thrush. As a result, infants, who have an undeveloped immune system, are typically the most likely to be diagnosed with thrush.
There are other causes of thrush, as well. For example, a person with a dry mouth may be more prone to the condition in certain circumstances. Specifically, if the person uses alcohol-based mouthwashes too frequently, it may cause dry mouth or a bacterial imbalance inside the mouth, which may allow the yeast to overgrow.
Pregnancy, poor dental hygiene, and using antibiotics are also causes of thrush. Each factor can create an imbalance of microorganisms inside the mouth. The imbalance leads to an excess of yeast, which can result in a thrush infection.
Thrush can spread from person to person. An infant can become infected during birth, particularly if a vaginal yeast infection was present at the time the infant came through the birthing canal. A toddler with a weak immune system may become infected if she shares toys, pacifiers, or bottle nipples with another child who is infected with thrush. In addition, an adult who wears dentures can spread the infection if she handles her dentures and then handles another object, such as flatware, that others put in their mouths. Consequently, the causes of thrush may vary depending on the circumstance, although the yeast itself must always be present for the infection to begin.
