DefinitionVon Willebrand disease is the most common hereditary bleeding disorder.Causes, incidence, and risk factorsVon Willebrand disease is caused by a deficiency of von Willebrand factor. Von Willebrand factor helps blood platelets clump together and stick to the blood vessel wall, which is necessary for normal blood clotting. There are several types of Von Willebrand disease.Von Willebrand disease affects men and women equally. Most cases are mild. Bleeding may occur after surgery or when you have a tooth pulled. Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) can make this condition worse. Bleeding may decrease during pregnancy.A family history of a bleeding disorder is the primary risk factor. In women with heavy or prolonged menstrual bleeding, von Willebrand is more