This woman's lifelong history of excessive bleeding suggests an inherited bleeding problem, as does the positive family history. The prolonged PTT indicates a deficiency of factors VIII, IX, XI, or XII, but the commonest of these deficiencies (classic hemophilia A and Christmas disease, or hemophilia B) are vanishingly rare in women. Furthermore, the continued oozing from dental sites and the absence of ecchymoses or hemarthroses suggest a platelet function disorder, as does the prolonged bleeding time. Von Willebrand disease is an autosomal dominant condition that leads to both platelet and factor VIII dysfunction and is the likeliest diagnosis in this patient. Although factor VIII concentrates can be used for life-threatening bleeding, most will respond to desmopressin, which raises the von Willebrand factor level in the most common form (the so- called type 1 form) of this disease. Mild von Willebrand disease is fairly common (1 in 250 individuals). Fresh frozen plasma and whole blood are much less effective ways to deliver factor YIII. Platelet transfusion would not be as effective as correction of the von Willebrand factor level.