Who Is At Risk for Excessive Blood Clotting?

People at highest risk for excessive blood clotting have both acquired and genetic risk factors. For example, if you have the Factor V Leiden mutation and atherosclerosis, and you smoke, you're at higher risk than someone who has only one of these risk factors.

See "What Causes Excessive Blood Clotting?" for more information on the diseases, conditions, and other factors that can lead to this condition.

Genetic Risk Factors

You're more likely to have a genetic cause of excessive blood clotting if you have:

• Family members who have had dangerous blood clots
• A personal history of repeated blood clots before the age of 40
• Had a heart attack or stroke before the age of 50
• Had unexplained miscarriages

Factor V Leiden is one of the more common genetic mutations that can alter the blood clotting process. It's found in 5 to 15 percent of the general population. This mutation accounts for up to a quarter of the cases of genetic blood clotting disorders. Factor V Leiden is found mostly in people who have a European background.

Other Risk Factors

Another risk factor for excessive blood clotting is antiphospholipid antibody syndrome linked to lupus. This condition may affect 4 to 14 percent of the U.S. population.