Deep vein thrombosis risk factors

Editors-in-Chief: C. Michael Gibson, M.S., M.D. Associate Editor-In-Chief: Ujjwal Rastogi, MBBS [mailto:urastogi@perfuse.org]

Overview
The presence of a risk factor plays a major role in the management of DVT. An understanding of the risk factors for venous thrombosis is necessary in order to maximize the prevention of this disease in high risk individuals and groups of patients. Furthermore,
 * Short-term anticoagulation is required for transient risk factors.
 * Long-term anticoagulation is given in following conditions
 * 1) Thrombosis due to an unknown cause.
 * 2) In chronic diseases like coronary artery disease
 * 3) Presence of persistent risk factors.

Risk factors for DVT can be sub-divided in various sections like
 * 1) Modifiable
 * 2) Non-Modifiable
 * 3) Temporary
 * 4) Potential New Risk Factors.

Modifiable risk factors
Obesity: Obesity is defined as a body-mass index (BMI) above 30 kg/m2. Underweight subjects have reduced risk while obese people have significant risk for DVT, and or PE.

In a number of high-risk settings such as Smoking, Use of hormonal contraceptive, and long flights, Obesity appears to be a contributing factor for further increasing the risk of VTE

Homocysteine Elevated homocysteine has been consistently reported as a risk factor for venous thrombosis and levels can be reduced with B vitamin supplementation

Smoking

Non-modifiable risk factors

 * Age: risk of DVT increases with age.
 * Inherited thrombophilia: which include the following disorder
 * Factor V Leiden mutation
 * Prothrombin gene mutation
 * Protein S deficiency
 * Protein C deficiency
 * Antithrombin (AT) deficiency

Temporary risk factors

 * A previous history of DVT (most significant risk factor).Cushman et al noted a 28-day case-fatality rate of 9.4% after first-time DVT and 15.1% after first-time PE.
 * Injury to a deep vein from surgery, fractured bone, or other trauma.
 * Prolong Immobilization : It slow down the blood flow in a deep vein. This may occur after surgery, if you're ill and in bed for a long time, or if you're on a long flight.
 * Pregnancy and the first 6 weeks after giving birth.
 * Recent or ongoing treatment for cancer.
 * A central venous catheter, a tube placed in vein to allow easy access to the bloodstream for medical treatment.