Venous Thromboembolism (VTE), which includes both deep vein thrombosis (DVT) and pulmonary embolism (PE), can develop due to a variety of risk factors that increase the likelihood of blood clot formation. These risk factors are often grouped into categories based on patient-specific characteristics, lifestyle factors, and medical conditions:
1. Patient-Specific Risk Factors
- Age: The risk of VTE increases with age, particularly after age 50.
- Family History: A family history of VTE increases an individual’s risk, suggesting a genetic predisposition to blood clotting disorders.
- Gender: Women may have a higher risk during pregnancy and when using hormonal birth control or hormone replacement therapy.
- Immobility: Prolonged immobility, such as bed rest during hospitalization, long-duration flights or travel, and sedentary lifestyle can lead to blood stasis and increase the risk of clot formation.
- Obesity: Excess body weight increases the pressure in the veins of the pelvis and legs, contributing to the risk of DVT.
- Smoking: Smoking affects blood clotting and circulation, which can increase the risk of VTE.
- Surgery: Major surgery, especially orthopedic, abdominal, or pelvic surgery, is a significant risk factor due to prolonged immobility and potential blood vessel damage during the procedure.
- Cancer: Certain cancers, particularly pancreatic, ovarian, and lung cancer, and their treatments can increase the risk of VTE due to elevated levels of clotting factors.
- Heart Disease: Conditions like heart failure increase the risk of VTE as poor heart function can lead to slower blood flow.
- Inflammatory Bowel Disease: Diseases such as Crohn’s disease and ulcerative colitis increase the risk of VTE.
- Pregnancy: Pregnancy increases the risk of VTE up to five times due to increased blood volume and hormonal changes that enhance blood clotting.
- Hormonal Therapy: Estrogen-based medications, such as birth control pills or hormone replacement therapy, increase the risk of clotting.
4. Acquired or Inherited Clotting Disorders
- Factor V Leiden and Prothrombin Gene Mutation: Genetic mutations that affect blood clotting mechanisms can significantly increase the risk of VTE.
- Antiphospholipid Syndrome: An immune system disorder that increases the risk of clotting.
- Individuals who have experienced VTE are at higher risk of future episodes, indicating a need for ongoing medical oversight and possibly long-term anticoagulation therapy.
6. Prolonged Hospital Stay or ICU Admission
- Extended periods of immobility associated with critical care or recovery from major illnesses or procedures can increase the risk of developing VTE.
Considering the variety of risk factors, preventive measures are tailored according to the individual risk profile, particularly for those undergoing surgery or with multiple risk factors. This may include the use of anticoagulants, mechanical methods like compression stockings or pneumatic devices, and ensuring early and adequate mobilization post-surgery or during long hospital stays.