Jaundice is defined as hyperbilirubinemia, a yellowing of the sclera, skin, mucous membranes, and other tissues and body fluids due to an increase in bilirubin in the blood. There are physiologic and pathologic. Physiological jaundice in newborns is generally not deep and is characterized by: 1. Jaundice usually begins to appear 2-3 days after birth. 2, jaundice gradually deepens, reaching a peak on the 4th-6th day, and then gradually decreases. 3, full-term birth of newborns, jaundice generally subsides in 2 weeks after birth, premature babies generally subsided in 3 weeks after birth. 4, the degree of jaundice is generally not deep, the skin color is light yellow, jaundice is often limited to the face and upper body, jaundice when the child’s general condition is good, normal body temperature, normal appetite, normal color of urine and stool, normal growth and development. 5.Serum bilirubin exceeds normal by 2mg/dl (34.2μmol/L) but is less than 12.9mg/dl (221μmol/L). If the child’s jaundice falls into this category, the parents i.e. there is no need to worry. Pathological jaundice has the following characteristics: 1, jaundice appears too early, within 24 hours after birth. 2, jaundice subsides too late, lasts too long, more than the normal time to recede, or jaundice has subsided and reappears, or jaundice in the peak time after the receding and progressive aggravation. 3, the degree of jaundice is too heavy, often spreading throughout the body, and the skin mucous membrane is obviously yellow. 4.The bilirubin exceeds 12.9mg/dl when the serum bilirubin is checked, or rises too rapidly, more than 5mg/dl per day. 5.In addition to jaundice, it is accompanied by other abnormalities, such as mental fatigue, less crying, less movement, less eating or unstable body temperature. In severe cases, pathological jaundice can be complicated by bilirubin encephalopathy, often called “nuclear jaundice”, which causes neurological damage and leads to serious sequelae such as mental retardation in children, or even death. Therefore, when a child has jaundice, any of the above five aspects should be taken seriously by parents so that pathological jaundice can be detected early for timely treatment.