Thrush is generally due to an imbalance in the microbial flora, leading to an infection by Candida albicans. It is common in newborns and infants. Children who have long-term malnutrition, diarrhea, or who have been treated with broad-spectrum antibiotics or corticosteroid hormones may also be susceptible to thrush. Additionally, if the mother has an infection with Candida albicans in the intestines, or if there is contamination on the nipple during breastfeeding, or if the nursing equipment is infected with fungi, this could also lead to the occurrence of thrush.