VSD is ventricular septal defect - a hole in the wall separating the right ventricle and the left ventricle. Whether a VSD will close naturally or not depends on its size, location, age of child, response of the body, etc. There are many unknown factors. A small muscular VSD is likely to close as the child grows up, while an outlet VSD will not close. Also, one should take into account the degree of leak of blood across the defect and the effect of such a shunt on the lung pressures and the blood vessels of the lung. A large hole leading to equalisation of pressures between the right and the left side probably needs to be addressed surgically and early surgery may be life saving. Later on, if permanent damage occurs to the lung vessels, the condition may become inoperable.