What is a pulmonary embolism?

A pulmonary embolism is specifically defined as the blockage of a pulmonary artery in the lungs by a substance that has traveled from elsewhere in the body, most commonly a blood clot. This condition can arise when deep vein thrombosis (DVT), which involves clot formation in the deep veins of the legs or other parts of the body, releases a clot that migrates through the bloodstream to the lungs.

When a blood clot reaches the lungs, it disrupts the normal blood flow, which can lead to significant impairments in gas exchange. Symptoms can include shortness of breath, chest pain, and coughing, particularly if there is associated bleeding. Immediate medical attention is often required because a pulmonary embolism can be life-threatening.

The other choices describe different respiratory or pulmonary conditions. For instance, fluid accumulation in the lungs pertains to pulmonary edema, chronic lung disease includes a range of long-term respiratory conditions such as COPD, and inflammation of lung tissue can relate to pneumonia or other conditions. However, none of these options accurately define a pulmonary embolism as clearly and precisely as the mention of a blood clot traveling to the lungs.