Does pulmonary embolism cause low blood oxygen levels?

In pulmonary embolism (PE), blood oxygen levels decrease; indeed, reduced arterial oxygen saturation is a hallmark feature of PE. Patients may also exhibit prominent symptoms such as cough, sputum production, dyspnea, chest tightness or chest pain, and hemoptysis. PE is a pulmonary vascular disorder, most commonly caused by deep vein thrombosis (DVT). Once a thrombus detaches, it travels via the bloodstream to the pulmonary arteries, where it can obstruct the main pulmonary artery or its branches, thereby precipitating clinical manifestations. Prompt anticoagulant therapy is strongly recommended.