Video - Pulmonary embolism

Pulmonary embolism (PE) is a blockage of the lungs main artery or one of its branches by a substance that has traveled from elsewhere in the body through the bloodstream (embolism). PE most commonly results from a deep vein thrombosis (commonly a blood clot in a leg) that breaks off and migrates to the lung, a process termed venous thromboembolism (VTE). This can cause serious damage to the lung tissue and can be life-threatening.

Symptoms vary by the amount of downstream lung tissue denied blood, which creates a ventilation-perfusion mismatch. They include shortness of breath, chest pain, and coughing. PE can also cause low blood oxygen levels, which can lead to confusion, loss of consciousness, and even death. Treatment of PE typically involves supportive therapy and blood thinning medications to dissolve the clot and prevent further clots from forming. Sometimes a filter is placed in the vena cava to trap clots before they reach the lungs.