Thrush is generally caused by a fungal infection due to an imbalance in the microbial flora, primarily involving the formation of a white plaque membrane by Candida albicans on the surface of the oral mucosa. It is mainly seen in individuals with lowered immunity, such as those with long-term malnutrition, repeated use of antibiotics, diarrhea, or the use of certain medications like corticosteroids. Additionally, unsanitary conditions during breastfeeding, fungal contamination on the mother's nipples, or fungal infection from nursing equipment can also lead to thrush. Typically, thrush does not require special antimicrobial medication. If the baby's immunity improves and their intestinal flora are properly established, thrush can heal spontaneously. It is generally recommended to orally take some probiotics and enhance oral care, which can include cleaning the oral cavity with 2% sodium bicarbonate before and after breastfeeding, or locally applying antifungal agents to suppress the fungal growth in the mouth.