Candidiasis is a fungal infection caused by the widespread yeast fungus Candida albicans. It is also called Candida mycosis or thrush.

Fungi like Candida albicans are present on the skin and mucous membranes of every person - that is completely normal. But sometimes, for example when the body's immune system is weakened, they get out of control. Candidiasis affects women more commonly than men. It usually affects the labia and the vagina. In men, it usually affects the glans and the foreskin.

In people with weakened immune systems, due to HIV for example, the mucous membranes of the mouth and throat, as well as the esophagus, can be affected.

If the infection causes bleeding in the vagina or on the foreskin, this raises the risk of HIV being transmitted. HIV-negative people with candidiasis have an increased risk of becoming infected with HIV because the inflammation allows the virus to enter the body more easily.