Pulmonary Embolism: A Modern Medical Analysis of Pathogenesis, Diagnosis, and Treatment

Pulmonary embolism is a life-threatening clinical syndrome situated at the intersection of internal medicine, cardiology, intensive care, and emergency medicine. In most cases it develops when thrombotic material formed in the deep veins of the lower extremities or pelvis migrates into the pulmonary arterial circulation and produces an abrupt obstruction of blood flow. The clinical importance of this disorder lies in its high early mortality, its heterogeneous presentation, and the fact that diagnostic delay remains common when symptoms are interpreted as pneumonia, acute coronary syndrome, anxiety-related dyspnea, pleurisy, or heart failure. This article analyzes pulmonary embolism from an integrated pathophysiological and clinical perspective. The review focuses on the mechanisms of venous thrombus formation, the consequences of embolic obstruction for pulmonary perfusion and right ventricular loading, the diagnostic role of clinical probability assessment, D-dimer testing, CT pulmonary angiography, echocardiography, and biomarker stratification, as well as the principles of anticoagulation, thrombolysis, catheter-directed therapy, and long-term prevention. The synthesis demonstrates that rapid recognition, structured risk stratification, and timely reperfusion or anticoagulant treatment remain the decisive factors that determine outcome.