How long it takes for a heart murmur to clear up in a newborn is related to the nature of his or her disease and cannot be generalized. Neonatal heart murmurs include physiologic and pathologic murmurs. Physiologic murmurs are heart murmurs of grade 3 or less, which are minor murmurs caused by unclosed foramen ovale or unclosed ductus arteriosus, and can gradually disappear on their own after 2-3 days of life. If the murmur is more than grade 3 due to congenital heart disease such as atrial septal defect and ventricular septal defect, it is called pathological murmur and cannot disappear by itself. Meanwhile, continuous fever, severe anemia, acute infection and other diseases can also cause heart murmur, which can disappear after the original disease is cured. Therefore, if you find a heart murmur, you should go to the hospital for an ultrasound examination of the heart in time, and if it is a pathological heart murmur, you should actively carry out treatment to avoid delaying the condition.