Von Willebrand disease is a blood clotting disorder. It's the most common genetic clotting disorder. It occurs in about one in one hundred people, although only one in one hundred of those will actually show serious symptoms. It can also be acquired as a secondary complication of other diseases, most commonly aortic valve stenosis, which leads to an immune response against the clotting factor in question. It encompasses three different disorders that affect either the quantity or quality of von Willebrand factor, a clotting factor, in the blood.
The most common type of the disorder is usually asymptomatic, although it can cause nosebleeds and, more rarely, other types of bleeding in uncommon situations. It's named after Finnish physician Erick Adolf von Willebrand, who first described it in 1926.
The condition is usually diagnosed by using antigens that bind to the von Willebrand factor to determine its concentration in the blood. However, other clotting tests can be suggestive of the condition.
The usual treatment is desmopressin, which can be administered after minor trauma, or in preparation for surgery or dental work. In women, the contraceptive pill works as an effective measure against excess menstruation.