What Increases Your Risk

Many things increase your risk for deep vein thrombosis (DVT). These include:

• Being older than 40.
• Being overweight.
• Not taking anticoagulant medicine as prescribed.

Other risks include things that cause slowed blood flow, abnormal clotting, and a blood vessel injury.

Slowed blood flow

Blood does not flow normally if you are not active for long periods of time. Examples include:

• Long-term bed rest, such as after a surgery, injury, or serious illness.
• Sitting for a long time, especially when traveling long distances.
• Leg paralysis.

Abnormal clotting

Some people have blood that clots too easily or too quickly. Problems that may cause increased clotting include:

• Inherited blood-clotting problems.
• Family history of close relatives, such as a sibling, who has had deep vein thrombosis or a pulmonary embolism.
• Cancer and its treatment.
• Blood vessel diseases, such as varicose veins, heart attack, heart failure, or a stroke.
• Pregnancy. A woman's risk for developing blood clots increases both during pregnancy and shortly after delivery or after a cesarean section.
• Using hormone therapy or birth control pills or patches.
• Smoking.

Injury to the blood vessel wall

Blood is more likely to clot in veins shortly after they are injured. Examples include:

• Recent surgery that involved the legs, hips, belly, or brain.
• Having a central venous catheter during a hospital stay.
• Injury, such as a broken hip.