<unk>  <unk>  is an acute obstruction of the<unk>  artery (or one of its branches). The obstruction in the<unk>  artery that causes a<unk>  can be due to thrombus, air, tumor, or fat. Most often, this is due to a venous thrombosis (blood clot from a vein), which has been dislodged from its site of formation in the lower extremities. It has then embolized to the arterial blood supply of one of the lungs. This process is termed thromboembolism.<unk>  is a potentially lethal condition. The patient can present with a range of signs and symptoms, including dyspnea, chest pain while breathing, and in more severe cases collapse, shock, and cardiac arrest.<unk>  treatment requires rapid and accurate risk stratification before the development of hemodynamic collapse and cardiogenic shock. Treatment consists of an anticoagulant medication, such as heparin or warfarin, and in severe cases, thrombolysis or surgery.<unk>  can be classified based on the time course of symptom presentation (acute and chronic) and the overall severity of disease (stratified based upon three levels of risk: massive, submassive, and low-risk).
Pulmonary embolism
Pulmonary hemorrhage
Pleural effusion
Lung infarction
Pulmonary aspiration
Air embolism
Aspiration pneumonia
Pleurisy