Learn About Pulmonary Embolism

Key Facts:

• A pulmonary embolism is a blockage (usually a blood clot) that stops blood flowing in one of the blood vessels within your lung.
• A pulmonary embolism is a medical emergency that can lead to death if untreated.
• A pulmonary embolism is often treatable with prompt diagnosis and administering medication to dissolve the clots, though full recovery may take months.

How Pulmonary Embolism (PE) Affects Your Body

Pulmonary embolism occurs when an artery in the lungs becomes blocked, most often by a blood clot. These clots usually form in the deep veins in the legs, known as deep vein thrombosis (DVT), but can also develop in the arms or pelvis. If left untreated, this clot may break free, travel through the bloodstream and lodge in the arteries of the lungs. This begins to block the normal flow of blood to the lungs and reduces blood oxygen levels in the entire body. In rare cases, the artery can be blocked by something other than a blood clot, such as an air bubble, part of a tumor, fat, amniotic fluid or infectious material. In certain situations, the artery obstruction can cause the heart to work too hard, which increases blood pressure in the lungs and can lead to pulmonary hypertension.

Who Is at Risk?

Many different factors can increase your risk of developing deep vein thrombosis and pulmonary embolism.

• Prior History: Around 33% of people affected by a deep vein thrombosis or pulmonary embolism will experience another clot or blockage within 10 years.
• Inactivity: Blood clots are more likely to form during prolonged periods of sitting such as during bed rest or air travel. Being immobile in the hospital, particularly after surgery or trauma, is a significant risk.
• Other Medical Conditions: A history of cancer, recent surgery, liver disease, inflammatory bowel disease, chronic kidney disease, heart disease, interstitial lung disease (ILD), COVID-19 or autoimmune disease (like lupus) can increase your risk. Cancers with metastasis can make clotting more likely. Chemotherapy can increase this risk as well.
• Major trauma: People who have been in a major trauma, like a car accident, may be at higher risk for blood clots.
• Tobacco Use: Smoking narrows and damages the lining of blood vessels, making it more likely for blood clots to form.
• Obesity: Being overweight increases the risk of blood clots especially in women who smoke or have high blood pressure.
• Supplemental estrogen: High estrogen in birth control pills and hormone replacement therapies can increase blood clotting factors.
• Pregnancy: You are four to five times more likely to develop clots during pregnancy and up to three months after giving birth. This is due to the blood changes during pregnancy, the weight of the fetus and uterus on pelvic veins and damage caused to veins during childbirth.
• Family History: While genetic causes of blood clots are less common than acquired ones, some people have an inherited genetic condition that affects the normal clotting processes in the blood. There are also inherited conditions that impact blood thickness, which can lead to increased clotting.