What blood condition is characterized by normal PT, normal platelet count, and abnormal bleeding time?

Von Willebrand's disease is characterized by normal prothrombin time (PT), normal platelet count, and abnormal bleeding time. This condition arises from a deficiency or dysfunction of von Willebrand factor, which plays a critical role in platelet adhesion and aggregation during the formation of a clot. In individuals with this condition, even though the PT is normal and the platelet count is unaffected, the bleeding time is prolonged due to the impaired ability of platelets to adhere properly to the site of a vascular injury.

In patients with von Willebrand's disease, the abnormal bleeding can manifest through easy bruising, prolonged bleeding from cuts, or excessive bleeding during surgical procedures. Because the underlying defect is related to the qualitative function of platelets rather than their quantity or the extrinsic coagulation pathway, both PT and platelet counts remain normal while bleeding times are affected, highlighting the unique profile of this condition. This makes it distinguishable from other coagulation disorders, where you would typically expect alterations in PT or abnormalities in the platelet count.