Thrush is an infection which affects many women at some time in their lives. It is caused by a yeast called Monilia or Candida albicans which many people have on their skin or sometimes in the mouth and bowl. Most of the time this yeast causes no harm and you would not know it was there at all. But sometimes it multiplies and many cause infections, such as nappy rash in babies and mouth infection in the elderly. There are many factors that can encourage yeast to multiply and cause thrush: -warmth and moisture -pregnancy -antibiotics -broken skin -general health -sex