Von Willebrand disease is the most common hereditary bleeding disorder.

Von Willebrand disease is caused by a deficiency of von Willebrand factor. Von Willebrand factor helps platelets to clump together and stick to the blood vessel wall, which is necessary for normal blood clotting.

Von Willebrand disease affects both men and women. 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 common in Caucasian women than African American women.

• Nose bleeds
• Bleeding of the gums
• Abnormal menstrual bleeding
• Bruising
• Skin rash

• Normal platelet count
• Prolonged bleeding time
• Reduced von Willebrand factor level
• Reduced platelet aggregation (platelet aggregation test)
• Ristocetin co-factor is reduced

This disease may also alter the results of the following tests:

• Factor VIII level
• Von Willebrand factor multimers