Congenital heart diseases are structural abnormalities present at birth that affect the normal formation and function of the heart. The most common types are ventricular septal defect (VSD), atrial septal defect (ASD), patent ductus arteriosus (PDA), tetralogy of Fallot, pulmonary stenosis, coarctation of the aorta, and transposition of the great arteries (TGA). Symptoms range from none to signs of heart failure. Treatment options include medical management, catheter-based procedures such as angioplasty or device closure, and open heart surgery to repair or palliate the defects. Prognosis depends on the specific type of congenital heart disease and whether complete repair is possible.