 Thrombosis is a multifactorial problem because there are often multiple reasons why a person might develop thrombosis . These risk factors may include any combination of abnormalities in the blood vessel wall , abnormalities in the blood flow ( as in immobilization ) , and abnormalities in the consistency of the blood . Thrombophilia is caused by abnormalities in blood consistency , which is determined by the levels of coagulation factors and other circulating blood proteins that participate in the " coagulation cascade " . 
