Coagulation factor testing is done to know there is enough coagulation activity in the body to control the process of blood clotting. Coagulation factor testing helps to determine if the level of a coagulation factor is less, absent, normal or elevated. Low coagulation factor activity results in reduced clot formation and hence excess bleeding. Increased coagulation factor activity leads to thrombosis and embolism. Individual coagulation factor activity tests may be done to evaluate the function of a specific factor. If the test result shows decreased activity, then antigen test may be done as an additional follow-up test. This helps to know if the low activity is due to less amount of a coagulation factor or due to decreased function of the coagulation factor. Coagulation factor testing is also advised if there is a family history of bleeding.