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