Thrush is a fungal infection of the mouth. It usually begins on the tongue and inside of the cheeks. It may also spread to the palate, gums, tonsils, and throat.

Severe, untreated thrush can spread to the:

  • Esophagus
  • Urinary tract
  • Whole body—systemic infection causes multiple organ failure and death
  • Thrush

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    Thrush is caused by a fungus. There are many microorganisms that normally live in the mouth. When these organisms become imbalanced, the fungus can grow and cause thrush. The imbalance of organisms may be caused by a medical condition or medication.

    Risk Factors

    Factors that may increase your baby's chance of getting thrush include:

  • Contamination from caregivers
  • Contamination during breastfeeding
  • Birth complications, such as preterm birth, premature rupture of membranes, or perinatal asphyxia
  • Very low birth weight babies admitted to neonatal intensive care
  • Vaginal yeast infection in the mother at the time of birth
  • Factors that may increase your child's chance of getting thrush include:

  • Use of antibiotics
  • Health conditions that suppress the immune system, such as:    
  • HIV infection
  • Cancer or medical treatments for cancer, such as chemotherapy
  • Congenital immune deficiencies
  • Prolonged illness
  • Conditions that cause a dry mouth
  • Use of medications that treat psychiatric conditions