A newborn is defined as 28 days from the ligation of the umbilical cord to the postnatal period. Clinically, full term means 28 full days, and in daily life full term means full 1 month and refers to 30 days. The neonatal period has special physiological characteristics, the most common is neonatal jaundice, we should pay attention to the changes in skin color, most newborns will have jaundice, if the degree of jaundice is relatively high, you need to promptly seek medical treatment to avoid complications. Resistance is also poor during the neonatal period, and neonatal pneumonia and neonatal sepsis are likely to occur. It is important to pay attention to reasonable care, monitoring temperature changes and scientific feeding. If your child is not responding well, eating less milk, or has an abnormal temperature, you need to seek medical attention promptly.