What Causes Pulmonary Embolism? Understanding the Risk Factors and Underlying Conditions
Uncovering the Origins of Pulmonary Embolism
Pulmonary embolism (PE) is a serious medical condition that occurs when a blood clot travels through the bloodstream and lodges in the arteries of the lungs, blocking blood flow. While it wasn't always recognized as a distinct diagnosis in the past, autopsies have since revealed that many cases previously labeled as sudden cardiac death were actually due to undiagnosed pulmonary embolism. This discovery has led to greater awareness and improved detection methods over time.
Major Causes and Contributing Medical Conditions
Several underlying health issues and physiological states can significantly increase the risk of developing a pulmonary embolism. Among the most common are post-surgical complications, especially following orthopedic procedures or trauma such as fractures. When patients remain immobile for extended periods, particularly during recovery, blood circulation in the lower limbs slows down dramatically. This stasis promotes the formation of deep vein thrombosis (DVT), which can dislodge and travel to the lungs—resulting in a life-threatening PE event.
Cancer and Hypercoagulable States
Individuals undergoing cancer treatment face an elevated risk due to the disease's impact on blood chemistry. Tumors can trigger a hypercoagulable state, where the blood becomes abnormally thick and more prone to clotting. Certain types of cancers, especially those affecting the pancreas, lung, brain, and female reproductive organs, are particularly associated with increased clotting tendencies. Chemotherapy and other treatments may further exacerbate this risk, making vigilant monitoring essential for oncology patients.
Inherited Thrombophilia: A Hidden Genetic Threat
Some people are born with a predisposition to excessive clotting, known as inherited thrombophilia or congenital thrombotic disorders. Conditions like Factor V Leiden mutation, protein C or S deficiency, and antithrombin III deficiency make individuals far more susceptible to venous thromboembolism (VTE), including pulmonary embolism. These genetic factors often go unnoticed until a major clotting incident occurs, highlighting the importance of family history evaluation in at-risk populations.
Other High-Risk Factors You Should Know
Beyond surgery and genetics, several vascular conditions contribute to clot development. Varicose veins, though often considered a cosmetic concern, reflect underlying venous insufficiency and impaired blood return from the legs. Over time, this can set the stage for clot formation. Similarly, inflammatory conditions like vasculitis damage blood vessel walls, creating rough surfaces where clots are more likely to form.
Lifestyle factors such as prolonged sitting during long-haul flights, obesity, smoking, and hormonal therapies—including birth control pills and hormone replacement therapy—also play significant roles. Pregnant women and those in the postpartum period are likewise at higher risk due to natural changes in coagulation during these stages.
Prevention and Early Detection Save Lives
Recognizing the warning signs—such as sudden shortness of breath, chest pain that worsens with breathing, rapid heart rate, and unexplained coughing—can be crucial. Early intervention with anticoagulant medications or, in severe cases, thrombolytic therapy can dramatically improve outcomes. Doctors often recommend compression stockings, early mobilization after surgery, and prophylactic blood thinners for high-risk individuals.
Understanding what causes pulmonary embolism empowers both patients and healthcare providers to take preventive action. With growing medical knowledge and better screening tools, many PE cases can now be avoided—or treated effectively before they become fatal.