Babies with blue around the mouth and nose, the following situations are common: First, it is a normal phenomenon, the baby is blue around the mouth and nose, but the baby’s general condition is good, the perioral cyanosis is not obviously related to breastfeeding, crying, crying bright, good physical development, mostly because of the presence of subcutaneous veins around the mouth, the baby’s skin is thin and tender, so that the veins reflect and appear blue. Second, abnormal cardiopulmonary function, when there is severe pneumonia or congenital heart disease, there will be perioral cyanosis, the baby’s general condition is poor, weak cry, after crying, feeding and other activities perioral cyanosis symptoms significantly aggravated, need to go to the hospital in a timely manner, cardiac ultrasound and X-ray chest X-ray and other tests.