This chapter delves into the intricate pathophysiology of cardiovascular diseases, emphasizing structural, functional, and congenital disorders. Key arterial conditions such as atherosclerosis, atheromas, and atherosclerotic aneurysms of the aorta are explored, alongside the clinical implications of aortic dissection and coronary atherosclerosis. Congenital heart anomalies, including atrial septal defect (ASD), ventricular septal defect (VSD), and Tetralogy of Fallot, are analyzed in terms of their embryological basis and clinical presentation. Disorders of cardiac valves, including bicuspid aortic valve, senile calcific aortic stenosis, and chronic rheumatic valvulitis, are examined, with emphasis on morphological and functional changes. Pathologies such as myocardial ischemia, myocardial infarction, and mural thrombosis highlight ischemic heart disease, while endocarditis (infective, marantic) and pericarditis (hemorrhagic, immune-mediated) illustrate inflammatory processes. Systemic conditions such as Marfan’s syndrome and systemic lupus erythematosus are discussed in relation to cardiovascular complications. This chapter also includes electrocardiogram (ECG) and echocardiogram findings for common cardiac disorders, providing essential diagnostic insights into structural and functional abnormalities of the heart. Advances in surgical interventions, such as coronary artery bypass, and modern diagnostic techniques are also covered. This comprehensive overview integrates clinical relevance with pathological findings, fostering a deeper understanding of cardiovascular diseases.