What is von Willebrand's disease?

Von Willebrand's disease is a bleeding disorder in which a protein in your body's blood system is missing or does not work well. The protein is called von Willebrand factor. If the von Willebrand factor is working properly, it helps your blood clot. Clotting stops the bleeding when you are cut or injured.

The von Willebrand factor usually carries another blood-clotting protein called factor VIII. If you have von Willebrand's disease, the two proteins may not attach properly to each other. Your blood will not clot as well as it should.

There are three major types of the disease:¹

• Type 1: A shortage of von Willebrand factor (mild). This type of von Willebrand's disease can result in mild to moderate bleeding episodes, depending on how much von Willebrand factor is missing. Between 70% to 80% of all cases of von Willebrand's disease are type 1.² Some people with type 1 disease do not need treatment and may not be aware that they have a blood disorder.
• Type 2: A flawed von Willebrand factor (usually mild). Although the body produces normal amounts of the von Willebrand factor, it doesn't work properly. Type 2 is further classified (such as 2a or 2b) depending on the type of flaw.
• Type 3: A complete lack of von Willebrand factor (more severe). Type 3 von Willebrand's disease is very rare. When the body does not produce von Willebrand factor, the cells (platelets) needed to form a clot do not work properly and clotting factor VIII levels are low, both of which can lead to severe bleeding. People with type 3 disease are in more danger of anemia and excessive bleeding after an accident or during surgery.

What causes von Willebrand's disease?

Von Willebrand's disease usually is passed down through families. It is the most common bleeding disorder present at birth (congenital)¹, but most cases are mild. About 1% of people may inherit this disease.³ If one parent has von Willebrand's disease, a child has a 50% chance of having the condition.¹ Men and women are equally likely to have von Willebrand's disease.

What are the symptoms?

Excessive bleeding is the main symptom of von Willebrand's disease. The severity of the condition varies from person to person, even within the same family.¹ Over half of all women with von Willebrand's disease have very heavy menstrual bleeding. Other symptoms include frequent nosebleeds and heavy bleeding after injury or surgery.¹

Von Willebrand's disease causes symptoms similar to the bleeding disorder hemophilia.

How is von Willebrand's disease diagnosed?

Von Willebrand's disease can be hard to diagnose. If you have symptoms that suggest a blood clotting disorder, your doctor will ask about your medical history, especially about episodes of excessive bleeding. Tests that can help with the diagnosis include:

• Blood tests that measure bleeding time, von Willebrand factor activity levels, or von Willebrand factor antigen.
• Genetic testing that shows a defect in your von Willebrand factor.