a blood substance involved in clotting; decrease in this factor is the most common inherited clotting disorder, and may be a reason for some women to have very heavy periods

The clotting protein that is deficient in VWD. The VWF is either present at lower than normal levels or does not work properly.

(noun) a protein, made in endothelial cells, which causes the platelets to bind to the damaged blood vessel wall (platelet adhesion).

A protein in the blood that is involved in normal blood clotting by binding to platelets. Abnormalities in the normal processing of von Willebrand factor are seen in patients with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome.

Von Willebrand factor is a blood glycoprotein involved in coagulation. It is deficient or defective in von Willebrand disease and is involved in a large number of other diseases, including thrombotic thrombocytopenic purpura, Heyde's syndrome, and possibly hemolytic-uremic syndrome.