From the Guidelines
Thrombosis, or the formation of blood clots, is primarily caused by a combination of factors including stasis of the blood, changes in the vessel wall, and changes in the composition of the blood, as outlined in the Virchow triad. These factors can be further divided into acquired risks, such as surgery, trauma, pregnancy, and the use of exogenous hormones, and genetic risks, including inherited thrombophilia 1. The risk factors for venous thrombosis are linked to the Virchow triad, which includes:
- Stasis of the blood
- Changes in the vessel wall
- Changes in the composition of the blood
Some of the specific factors that have been identified as increasing the risk of thrombosis include:
- Deficiency of antithrombin III, protein C, and protein S
- Factor V Leiden positivity
- Use of oral contraceptives
- Hyperhomocysteinemia 1
It is essential to note that these factors can contribute to the development of thrombosis by altering the body's natural clotting mechanism, leading to the formation of blood clots. To reduce the risk of thrombosis, it is crucial to address these underlying factors and maintain a healthy lifestyle, including staying hydrated, moving regularly, and avoiding smoking. In some cases, anticoagulant medications may be prescribed to prevent the formation of blood clots.
From the FDA Drug Label
People with atrial fibrillation (a type of irregular heartbeat) are at an increased risk of forming a blood clot in the heart, which can travel to the brain, causing a stroke, or to other parts of the body.
The cause of thrombosis (blood clots) is not explicitly stated in the provided text, but it is mentioned that people with atrial fibrillation are at an increased risk of forming a blood clot in the heart. Additionally, it is stated that stopping apixaban increases the risk of forming a clot in the blood, suggesting that the underlying condition or the cessation of anticoagulant therapy may contribute to the formation of blood clots. 2
From the Research
Causes of Thrombosis
Thrombosis, or blood clots, can be caused by various factors, including:
- Abnormal clot structure, which has been identified in patients with thrombotic disorders 3
- Inherited disorders of blood coagulation, such as deficiencies of coagulation factors 4
- Inhibitors to clotting factors, including natural inhibitors like antithrombin III, protein S, and protein C, as well as acquired inhibitors like antibodies that neutralize specific clotting proteins 5
- Imbalance in the regulation of clotting factors, which can lead to unregulated clotting and thrombosis 6
- Deficiencies in clotting factors, such as factor IX and thrombin, which can be diagnosed using biosensors and other detection methods 7
Clotting Mechanism
The clotting mechanism involves a complex sequence of events, including:
- The release of tissue factor, which initiates the blood coagulation cascade 4, 6
- The activation of coagulation factors, which ultimately leads to the conversion of fibrinogen to fibrin and the formation of a blood clot 4, 6
- The regulation of clotting factors by natural inhibitors, such as antithrombin III, protein S, and protein C, which helps to control the coagulation response and limit the extension of the clot 5, 6
Risk Factors
Certain risk factors can increase the likelihood of thrombosis, including:
- Abnormalities in the coagulation cascade, such as deficiencies of coagulation factors 4
- The presence of inhibitors to clotting factors, such as antibodies that neutralize specific clotting proteins 5
- Imbalance in the regulation of clotting factors, which can lead to unregulated clotting and thrombosis 6
- Deficiencies in clotting factors, such as factor IX and thrombin, which can increase the risk of bleeding and thrombosis 7