What is Factor V Leiden?

By: Alere Staff

Factor V Leiden is an inherited genetic clotting disorder.1 Blood needs to be in liquid form to carry oxygen and nutrients to all of the body’s organs and tissues.2 In response to injury or bleeding, the blood needs to be able to form a clot to stop this bleeding.

Factor V is a protein that helps the body form blood clots normally in response to injury or bleeding. Some people are born without this protein and instead have a different form called Factor V Leiden. Factor V Leiden increases the chances of forming abnormal blood clots especially in the deep veins of the legs (DVT).1 These abnormal clots can be dangerous.

Factor V Leiden is diagnosed by a blood test. Many times patients are tested for this disorder after they are treated for a DVT or a family member has a DVT or blood clot to the lungs and the disorder was found. The treatment of an abnormal blood clot is to take an anticoagulant such as warfarin or another brand name like Coumadin®. Anticoagulants help prevent any further development of abnormal clots.

Patients with DVT that do not have Factor V Leiden, may only require anticoagulation for a short time as determined by their doctor. Patients with Factor V Leiden may require lifelong treatment with anticoagulants to prevent dangerous formation of clots.2

Find out more about DVT and blood clots in our articles March is DVT Awareness Month: Understanding Your Risk of DVT or Compression Stockings for DVT (Deep Vein Thrombosis).

  1. Kujovich JL. Factor V Leiden thrombophilia. Genetic Medicine. 2011;13:1.
  2. Ornstein DL, et al. Factor V Leiden. Circulation. 2003;107:1.


COUMADIN® is a registered trademark of Bristol-Myers Squibb Pharma Company. Alere is not affiliated or associated with Bristol-Myers Squibb Pharma Company or the COUMADIN® trademark.


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