The risk factors for deep vein thrombosis (DVT) include:
- A history of DVT.
- Conditions or factors that make your blood thicker or more likely to clot than normal. Some inherited blood disorders (such as factor V Leiden) will do this. Hormone therapy or birth control pills also increase the risk of clotting.
- Injury to a deep vein from surgery, a broken bone, or other trauma.
- Slow blood flow in a deep vein due to lack of movement. This may occur after surgery, if you're ill and in bed for a long time, or if you're traveling for a long time.
- Pregnancy and the first 6 weeks after giving birth.
- Recent or ongoing treatment for cancer.
- A central venous catheter. This is a tube placed in a vein to allow easy access to the bloodstream for medical treatment.
- Older age. Being older than 60 is a risk factor for DVT, although DVT can occur at any age.
- Overweight or obesity.
Your risk for DVT increases if you have more than one of the risk factors listed above.