If hemophilia is suspected or if you appear to have a bleeding problem, your doctor will take a personal and family history, do a physical exam, and order blood tests. 

Blood Tests Are Used To Determine

• How long it takes for your blood to clot
• Whether your blood has low levels of any of the clotting factors
• Whether one of the factors is completely missing from your blood

The test results will show if you have hemophilia, what type of hemophilia you have, and how severe it is. Hemophilia A is diagnosed by testing the level of factor VIII coagulation activity in the blood. Hemophilia B is diagnosed by measuring the level of factor IX activity. If the mother is a carrier, testing can be done before a baby is born. Prenatal diagnosis can be done at 9 to 11 weeks by chorionic villus sampling (CVS) or by fetal blood sampling at a later stage (18 or more weeks). These tests can be done at a hemophilia treatment center.