In general, the relative size of a ventricular septal defect does not get larger. The absolute area of a ventricular septal defect increases accordingly with the increase in heart size. In adults with ventricular septal defects, cardiac blood flow shunts left to right due to hemodynamic factors. In addition, as the patient ages, the cardiac load increases, blood flow to the pulmonary circulation increases, pulmonary hypertension develops, and heart failure occurs. With this, the heart gradually enlarges and in turn the size of the ventricular septal defect increases accordingly. In congenital ventricular septal defects in infants and young children, as the heart develops, and as cardiac function declines and heart failure develops, the heart increases in size, and the area of the ventricular septal defect increases, but the relative proportion of the defect does not increase. When ventricular septal defects occur, it is necessary to actively consult the doctor and follow the doctor’s instructions for rational treatment.