Imbalance of normal bacteria in the mouth that leads to an overgrowth of the Candida fungus, the same fungus that causes vaginal yeast infections, causes oral thrush, according to WebMD. Certain medications, certain medical conditions and stress may cause this imbalance.
Medications that may cause oral thrush include corticosteroids, birth control pills and antibiotics, as stated by WebMD. Pregnant women and persons with cancer, an HIV infection, dry mouth and uncontrolled diabetes have an increased risk of developing thrush. Improperly fitting dentures and smoking can have the same effect, and breastfeeding babies can pass thrush to their mothers. Quitting smoking, avoiding the overuse of mouthwash that kills micro-organisms, receiving regular dental checkups, limiting sugar intake and practicing good oral hygiene prevent oral thrush.
The characteristic sign of thrush is the appearance of raised, creamy-white lesions on the tongue or other parts of the mouth that may look like cottage cheese, as confirmed by WebMD. These lesions may be painful or bleed when scraped or brushed, and they often appear suddenly. Treatment generally consists of an anti-fungal medication that the patient takes over the course of 10 to 14 days. The patient may also need treatment for an underlying medical problem.