In a pulmonary embolism a lung artery, which transports the blood from the heart to the lung tissue, is clogged. For this reason, some doctors also call this a pulmonary artery embolism. In most cases a thrombosis is the cause. As a rule, this is released from the arteries of the lower leg and runs with the blood through the heart and finally through into the lungs. Depending on the size, the thrombus (blood clots) blocks the smaller or larger pulmonary arteries there. This means a part of the lung is cut off from the blood circulation.
Bone breaks can also trigger a lung embolism. This happens when fatty bone marrow reaches the lung arteries through the bloodstream. Further pulmonary embolism causes are the entry of large amounts of air (air embolism, for example through faulty IV injections or infusions) or amniotic fluid (in pregnant women during delivery) into the bloodstream.
Pulmonary embolisms can occur in the smallest blood vessels and be almost asymptomatic. The disease is then sometimes discovered by accident. On the other hand, a pulmonary embolism can have a severe course, so that a circulatory arrest sets in within a very short time. If a large lung area is affected, doctors refer to this as a fulminant pulmonary embolism.
A pulmonary embolism on both sides leads to death in most cases. While no exact epidemiological data are available, the incidence of pulmonary embolism is estimated to be approximately 60 to 70 per 100,000 of the general population. Most often lung embolisms occur between the ages of 80 and 85. During pregnancy and during the administration of contraceptive pills there is also an increased risk of disease.