Epidemiology, Pathophysiology, Stratification, and Natural History of Pulmonary Embolism.

Pulmonary embolism (PE) is a common and potentially fatal form of venous thromboembolism that can be challenging to diagnose and manage. PE occurs when there is obstruction of the pulmonary vasculature and is a common cause of morbidity and mortality in the United States. A combination of acquired and inherited factors may contribute to the development of this disease and should be considered, since they have implications for both susceptibility to PE and treatment. Patients with suspected PE should be evaluated efficiently to diagnose and administer therapy as soon as possible, but the presentation of PE is variable and nonspecific so diagnosis is challenging. PE can range from small, asymptomatic blood clots to large emboli that can occlude the pulmonary arteries causing sudden cardiovascular collapse and death. Thus, risk stratification is critical to both the prognosis and management of acute PE. In this review, we discuss the epidemiology, risk factors, pathophysiology, and natural history of PE and deep vein thrombosis.