What Are the Causes of an Oral Yeast Infection?

by Annie Wang

Overview

An oral yeast infection, commonly referred to as thrush, is characterized by whitish lesions on the tongue. Thrush can spread from the mouth to the esophagus, lungs and skin. There are many different causes of thrush.
HIV/AIDS

Because HIV and AIDS compromise the effectiveness of the body's immune system, patients suffering from HIV/AIDS may have the inability to repel fungi such as yeast. A proliferation of yeast in the mouth is the cause of thrush.

Diabetes

Because people with diabetes tend to have saliva that contains significant amounts of sugar, their mouths can become breeding grounds for thrush-causing yeast.
Cancer

Cancer, as well as the treatments used to combat cancer, may suppress a patient's immune system so it cannot properly balance the microorganisms living within the body, such as yeast, causing thrush.
Antibiotics

Antibiotics may kill too many of the body's "good" microorganisms, which keep yeast in check. A patient undergoing a course of antibiotic treatment may develop thrush because the antibiotics killed the microorganisms which normally balance the proliferation of oral yeast.
Dry Mouth

Dry mouth is a condition in which not enough saliva is produced. When there's not enough saliva to keep the mouth moist and healthy, an oral yeast infection can set in.