Pulmonary embolism involves a blood clot clogging the arteries of the lungs. This means that it is more difficult for the heart to pump blood through the lungs and thus more difficult to oxygenate blood.
This leads to the individual experiencing shortness of breath and, at worst, circulatory shock and death. The blood clot in pulmonary embolism often comes from the legs.
Pulmonary embolism is a common cause of sudden death. The presence of pulmonary embolism in the population is estimated to be 0.5-1 / 1000 but is increasing dramatically to about 1/100 in people who are 70 years or older. Pulmonary embolism is often difficult for health services to diagnose since the symptoms are often nonspecific and patients rarely exhibit a typical clinical picture. Symptoms depend in part on the size of the pulmonary embolism and which parts of the lungs are affected. Many of the patients who suffer from pulmonary embolism are usually older and also suffer from other diseases, especially heart and lung diseases, which further complicates diagnosis.