Yeast infections are a common problem, particularly in people over the age of 40. Yeast infections occur when the yeast fungus grows out of control and causes an infection in the body. The most common places where yeast fungus can grow are the vagina, rectum, and mouth. In women, yeast infections are especially common during periods when there is a lot of change (like during menstruation).

The main way that yeast cause infections is by secreting a sticky film called hyphae which binds to cells and starts to digest them. This process can cause inflammation and pain which leads to treatment with antibiotics or antifungal medication. Yeast can also spread from one person to another through contact with saliva or mucus. In some cases, symptoms may not appear for several days after contact has been made.