Thrush is caused by Candida albicans infection, which forms a white flap on the surface of the oral mucosa, and is a common disease of the oral cavity in children. The disease is mostly seen in infants and young children within 2 years of age. Typical symptoms: a. The oral mucosa appears milky white, slightly elevated flap, with no inflammatory reaction around it. Shaped like a milk lump, painless, wipe off the flap can be seen below the non-bleeding red trauma. The flap area varies in size and can appear on the mucosa of the tongue, cheek, frontal, jaw, and inner lip. Second, it is found on the mucosa of the cheek, tongue, soft palate and mouth and lips. The white patches are not easily wiped off with cotton swabs or wet wipes. Third, when the infection is mild, the white patches are not easily detected and there is no obvious pain, or there is only a painful expression when eating. In severe cases, children are irritable, have poor appetite, cry and have difficulty in breastfeeding due to pain, sometimes with mild fever. Other symptoms, the damaged mucous membrane is not treated in time, it can continuously expand and spread to the pharynx, tonsils, gums, and in serious cases, it can stretch to the esophagus and bronchus, causing Candida esophagitis or Candida pneumonia and respiratory difficulties.