1.**Hemodynamic Instability**: In severe cases, the increased strain on the right ventricle can lead to a drop in cardiac output and systemic hypotension, potentially leading to shock and death.**Clot Formation (Thrombogenesis)**: Clots form in the deep veins due to factors described by Virchow's triad: endothelial injury, hypercoagulability, and venous stasis.**Ventilation-Perfusion Mismatch**: The obstruction impairs gas exchange by causing areas of the lung to be ventilated but not perfused (dead space), leading to hypoxemia (low blood oxygen levels).**Vascular Obstruction**: This blockage leads to increased pulmonary vascular resistance and a subsequent rise in right ventricular afterload.2.3.4.5.6.7.