I believe that many parents will be informed by the doctor that their child has a heart murmur when they take their child for a medical checkup. Usually parents are more nervous when they hear it, is there something wrong with my child’s heart? My personal experience: in the first week of life, about 2-3 out of 10 children will hear a murmur; at the 42-day checkup, about 1 out of 10 children will hear a murmur. The ability to hear a murmur also depends on factors such as the loudness of the murmur, the speed of the heartbeat, whether the child is quiet, and the attention of the doctor. The percentage of children with true congenital heart disease is about 1 in 100, with 10-15% having complex congenital heart disease, and not all congenital heart disease has a murmur. There are also children who are born without a murmur and only develop one later in life. How a murmur comes about: Rapid blood flow through large blood vessels, valves in the heart, or abnormal channels form. It is the same as a whistle that makes a sound. The murmur can be divided into physiological and pathological, general characteristics of the physiological murmur include: 1, only in systole, not in diastole 2, short duration, soft sound 3, the sound can be enhanced with fever or exercise 4, can change with the change in position 5, not related to the accelerated heartbeat or wheezing 6, will not conduct 7, no symptoms Pathological murmur characteristics include: 1, all diastolic murmurs are pathological 2, all systolic murmurs 3, end-systolic murmurs 4, murmurs of more than 3 levels 5, continuous murmurs 6, with abnormal heart morphology 7, with symptoms: shortness of breath, easy fatigue, poor growth, cyanosis, pestle finger, liver enlargement The aforementioned points of identification basically need a doctor’s auscultation, parents have no way to judge by themselves, so regular medical examination is very important. In the first few months of life, some pathological murmurs are obvious and accompanied by symptoms, which are easy to identify; others have no symptoms or even no murmur, which are not easy to detect. In general, newborns with a slight murmur that is asymptomatic can be rechecked at the 3-month checkup, and if there is still a significant murmur, it is best to go to a cardiologist for an examination. Sometimes I get stumped when I encounter a very mild murmur, such as a soft unconducted class I systolic murmur (the kind that requires very quiet and careful listening to hear).