The yeast that is responsible for vaginal infections and oral thrush is a tiny fungus called Candida albicans. Occasionally, a yeast infection is caused by a form of Candida yeast other than the common C. albicans. These yeasts include C. dubliniensi and C. stellatoidea. Tests can be done to determine what type of yeast is causing an infection, but infections by yeasts other than Candida albicans are rare.

Candida is the most common type of fungal infection in humans, and it can lead to serious health problems for some people. A yeast infection can even be deadly in people with compromised immune systems. For this reason, any woman who gets the symptoms of a yeast infection while receiving chemotherapy treatment for cancer should seek medical attention as soon as possible.