What is a pulmonary embolism?

A pulmonary embolism is defined as a blockage in one of the pulmonary arteries in the lungs, which is most commonly caused by blood clots that travel to the lungs from the deep veins in the legs, a condition known as deep vein thrombosis (DVT). Understanding that pulmonary embolism is closely associated with clots is crucial, as these clots can originate from various locations within the body before traveling to the pulmonary circulation.

In this context, the option that suggests a clot that travels to the lung accurately captures the essence of pulmonary embolism. The significance of this definition lies in its implications for patient care and the potential severity of the condition. A pulmonary embolism can lead to serious complications such as reduced oxygen levels, lung infarction, and can even be life-threatening if not diagnosed and treated promptly.

The details surrounding the other choices clarify why they do not align with the medical definition of a pulmonary embolism. A lung infection spreading from the bloodstream is indicative of a systemic infection or sepsis rather than a clot. Clots forming in the knee joint might refer to a localized thrombus, which is irrelevant to the pulmonary system. Lastly, abnormal chest wall movement could pertain to conditions like respiratory distress or musculoskeletal issues, but it does