Problems involved in grading the severity of hemophilia by test results.

Some problems involved in grading the severity of hemophilia were discussed. No definite correlation existed between the clinical severity of hemophilia and the results of coagulation tests (activity of deficient factors, whole blood clotting time, thromboplastin screening test). There was also no correlation between the presence or absence of oral bleeding or hemarthrosis and the test results. It was concluded that the clinical severity of the disease can be graded more reasonably on the basis of clinical hemorrhagic symptoms than according to the activity of deficient factors.