Most congenital heart diseases are prone to repeated respiratory infections due to increased pulmonary blood, and repeated respiratory infections further lead to heart failure, which are often causal factors and become the cause of death in congenital heart disease. Heart murmur: Most congenital heart disease can be heard murmur, this murmur is relatively loud, rough, serious cases can be accompanied by tremor in the anterior chest area. Most heart murmurs are detected by the physician at the time of the visit. Some normal children may have a physiologic murmur. Cyanosis Cyanosis is a prominent manifestation of cyanotic congenital heart disease (e.g., transposition of great vessels, tetralogy of Fallot, etc.). It can persist after birth or become gradually apparent three to four months after birth, and is most pronounced in the lips of the mouth, the beds of the finger (toe) nails, and the tip of the nose. For example, ventricular septal defect, atrial septal defect, and arteriovenous ductus arteriosus do not usually have cyanosis, but only appear when moving, crying, breath-holding, or suffering from pneumonia, and persistent cyanosis can occur in late stages of pulmonary hypertension and right heart failure. Poor physical strength Due to poor cardiac function, insufficient blood supply and hypoxia, seriously ill children have feeding difficulties in infancy, stopping after a few sips, shortness of breath, easy vomiting and profuse sweating, prefer to be held vertically, older children are reluctant to move, prefer to squat, easy fatigue after activity, paroxysmal dyspnea, severe hypoxia often faint suddenly when breastfeeding, crying or stooling, easy to develop heart failure. Poor development Congenital heart disease mostly has delayed development, especially in those with cyanosis, and in severe cases, intellectual development may also be affected. If the left atrium of congenital heart disease is enlarged or the pulmonary artery compresses the recurrent laryngeal nerve, the patient will have hoarse crying, shortness of breath and coughing since childhood; the enlarged ventricle may cause bulging of the precordial area and thoracic deformity; persistent cyanosis may be accompanied by pestle finger, which is formed 1 to 2 years after the appearance of cyanosis.