A Pulmonary Embolism (PE) is a life-threatening blockage of an artery in the lungs, typically caused by a blood clot (embolus) that has traveled from another part of the body, usually originating as a Deep Vein Thrombosis (DVT) in the legs. PE and DVT are collectively referred to as Venous Thromboembolism (VTE). Recognizing the factors that increase your risk is the single most important step in prevention, as avoiding DVT is the best way to prevent a PE.
The development of blood clots is often understood through Virchow’s Triad, a concept that outlines three main contributing factors:
- Hypercoagulability: The blood’s increased tendency to clot.
- Venous Stasis: Slowed or stagnant blood flow.
- Endothelial Injury: Damage to the inner lining of the blood vessels.
Major Risk Factors for Pulmonary Embolism
These factors are known to create a high-risk environment for VTE formation:
- Deep Vein Thrombosis (DVT) History: A previous episode of DVT or PE is the most significant risk factor for recurrence. A coexisting DVT is present in up to 50% of people with PE.
- Prolonged Immobility: Extended periods of limited mobility, which causes blood flow to slow (venous stasis), significantly increase risk. This includes:
- Bed Rest for longer than 3 days, often due to hospitalization or serious illness.
- Long-Duration Travel (over 4 hours), such as on flights or long car trips.
- Recent Surgery or Trauma: Major orthopedic surgery, particularly hip or knee replacement, is high-risk. Recent trauma or a fracture of a lower limb is also a significant factor due to vascular injury and subsequent immobility.
- Active Cancer: Malignancy, especially advanced or metastatic stage, is a strong risk factor, as cancer can cause the release of pro-clotting agents into the bloodstream (hypercoagulability).
- Cardiovascular Conditions: Diseases like chronic heart failure and atrial fibrillation impair blood flow and increase the likelihood of clotting.
Other Significant and Compounding Risk Factors
Several other conditions, which often combine to heighten the overall risk, must also be considered:
- Age: The risk of PE increases with age, doubling for every 10 years after age 25, and is notably high in individuals over 60.
- Hormone Use: The estrogen in combined oral contraceptives and hormone replacement therapy (HRT) can increase the production of clotting factors.
- Pregnancy and Postpartum: The risk is elevated during and immediately after pregnancy due to mechanical pressure on pelvic veins and natural changes in the blood’s clotting ability (hypercoagulable state).
- Obesity: Excess weight (BMI > 30) puts additional pressure on the leg veins, contributing to poor blood flow and increasing clot risk.
- Smoking: Toxic chemicals in cigarettes damage the blood vessel lining, making clot formation more likely.
- Genetic Factors: Inherited clotting disorders, or thrombophilia, such as Factor V Leiden mutation or Prothrombin gene mutation, increase the natural tendency to clot.
- Varicose Veins: Enlarged veins in the legs are associated with reduced blood flow (venous stasis) and are considered a risk factor for DVT.
Prevention and Proactive Care Strategies
Preventing a PE is achieved by aggressively preventing DVT, especially in high-risk patients. You can take several proactive steps:
- Increase Mobility: This is paramount. Get up and walk as soon as safely possible after surgery or trauma. During long periods of sitting, take breaks to walk around and perform ankle exercises (bending and rotating your ankles) every 15 to 30 minutes.
- Compression Therapy: Wear compression stockings as recommended by your doctor, especially during long periods of immobility, long-distance travel, or recovery, to help move blood efficiently and prevent pooling in the legs.
- Anticoagulants: People at high risk are often prescribed blood-thinning medications (anticoagulants) before and after surgery, or during periods of prolonged bed rest, to prevent clot formation.
- Lifestyle Changes: Quitting smoking, maintaining a healthy weight, and staying well-hydrated are crucial long-term strategies for reducing risk.
If you have multiple risk factors or experience any symptoms of DVT (unexplained leg pain, swelling, redness) or PE (sudden shortness of breath, chest pain, dizziness), talk to us. Dr. Douglas Stafford the Inland Northwest vein expert at Venia can help you!
Frequently Asked Questions
Is a DVT the only cause of a Pulmonary Embolism?
No. While DVT is the cause in up to 85% of cases, less common causes of a blockage include air bubbles, fat from a broken bone, or parts of a tumor that travel to the lungs.
How does my past medical history affect my PE risk?
A history of previous DVT or PE significantly increases your risk of recurrence. Additionally, chronic conditions like heart failure, chronic obstructive pulmonary disease (COPD), and hypertension are considered risk factors.
Do varicose veins increase my risk for PE?
Yes. Varicose veins are associated with slowed blood flow (venous stasis) and are considered a risk factor for DVT, which is the most common precursor to PE.
Should I wear compression stockings on long flights?
If you are at risk, wearing compression stockings on long flights or car trips is advised to help keep blood from pooling in your legs. You should also move in your seat and walk around every hour or so.