The yellowish face of a three-year-old child may be related to malnutrition, or it may be caused by iron deficiency anemia and abnormal liver function. 1. Malnutrition: If a three-year-old child is chronically picky about food and partiality, resulting in the body’s inability to consume sufficient nutrients, which can easily lead to malnutrition, he or she may show a yellowish color, which may also be accompanied by a lack of appetite, low immunity, and a lack of concentration. 2. Iron deficiency anemia: If the three-year-old child’s long-term eating habits are not good, it is easy to induce iron deficiency anemia, which may cause yellowish color, may also be accompanied by poor appetite, weakness and other manifestations. 3. Liver function abnormalities: three-year-olds infected with hepatitis C virus, hepatitis B virus, etc., easily caused by transaminases, bilirubin elevated, resulting in liver function abnormalities, which may cause yellowish color, may also be accompanied by loss of appetite, general weakness and other symptoms. The yellowish color of a three-year-old child may also be caused by other reasons, if accompanied by obvious symptoms of discomfort, you should consult a doctor as soon as possible, through the improvement of the relevant examination, to confirm the diagnosis of the cause, and then give targeted treatment.