What is von Willebrand Disease (VWD)?
Von Willebrand disease (VWD) is a type of bleeding disorder. "Bleeding disorders" is a general term for a wide range of medical problems that lead to poor clotting and continuous bleeding. Healthcare providers call these conditions by many different terms, including coagulopathy, abnormal bleeding and clotting disorders. von Willebrand disease is the most common bleeding disorder, affecting an estimated 1/100-1/10,000 in the US. It affects men and women equally.
VWD is caused by a problem with one of the proteins in the blood called von Willebrand factor, or VWF. VWF plays very important roles in helping the blood clot. People with VWD either don’t have enough VWF or what they have doesn’t work properly.
There are several types of VWD:
The most common and usually mildest form, however some with type 1 can have moderate or severe bleeding symptoms. A person with type 1 VWD has lower-than-normal levels of VWF and may also have lower levels of factor VIII, which is another type of blood-clotting protein.
The body makes normal amounts of VWF but it does not work the way it should.
Type 2 VWD is further broken down into 4 subtypes—2A, 2B, 2M and 2N—depending on the specific problem with the person’s VWF. Each type is treated differently.
- Subtype 2A: VWF levels are reduced, and platelets do not clump together adequately
- Subtype 2B: Although the VWF itself is defective, the ability of platelets to clump together is actually increased
- Subtype 2M: VWF levels are decreased, and the interaction of VWF with platelets or connective tissue is reduced
- Subtype 2N: Binding of VWF to factor VIII is markedly decreased
Most severe form of VWD; a person has very little or no VWF, and low levels of factor VIII.
Are there other bleeding disorders?
In addition to VWD, many other types of bleeding disorders exist, including:
There are several types of hemophilia. The two most common are:
Hemophilia A (Factor VIII deficiency)
Hemophilia B (Factor IX deficiency)
There are several rare, inherited bleeding disorders in which one or more clotting factors are missing, are produced in small amounts or don’t work properly.
There are several rare bleeding disorders in which platelets lack a protein needed for blood to clot.
Bleeding disorders vary greatly in severity and frequency.
Each bleeding disorder has a range of severity, from mild to moderate, to severe. Each of these disorders causes bleeding and each can be treated.
For more information, visit NHF’s Steps For Living, our premier educational website for people living with bleeding disorders.
What happens when a person bleeds?
When the body is injured, it starts to bleed. The bleeding stops when a clot forms. When blood clot formation occurs properly, a platelet plug is formed and holds together firmly at the site of the injury.
People who have a bleeding disorder are unable to make strong clots quickly or at all.
People with von Willebrand disease either don’t have enough von Willebrand factor (VWF, a protein in the blood) or the VWF they do have does not work properly. VWF plays two very important roles in helping the blood clot.
VWF makes platelets stick to the wall of an injured blood vessel and to each other. Without it, a platelet plug cannot be made. VWF is also a called a carrier protein because it carries one of the clotting factors, factor VIII, with it. This means that it helps make sure there is enough factor VIII in the blood and that it gets to where it’s needed. Without VWF, factor VIII will be broken down in the bloodstream and there may not be enough of it to stop bleeding.
Visit NHF’s Steps For Living, our premier educational website for people living with bleeding disorders, to see the clotting process in action.
Why is it important to know if I have von Willebrand Disease?
Finding out that you have von Willebrand disease (VWD) and getting the medical help you need can improve your daily quality of life and reduce stress. Besides being an inconvenience, heavy bleeding can be a health risk. The blood loss can cause anemia, or iron-poor blood. Anemia means you have a low red blood cell count in your blood. Untreated bleeding disorders can cause dangerous bleeding after:
- Dental work
- Any surgery, whether minor or major
These bleeding problems can be prevented or controlled with treatment. If you have symptoms of VWD, talk to your healthcare provider.
What are the symptoms of von Willebrand disease?
Finding out that you have von Willebrand disease (VWD) and getting the medical help you need can really improve your quality of life and reduce stress.
Talk to your healthcare provider, if you’ve experienced any of these symptoms:
- Have been told you are “low in iron” or have been treated for anemia
- Have experienced heavy bleeding after any surgery, including dental surgery
- Have frequent nosebleeds that last longer than 10 minutes
- Have bleeding from cuts or injuries that lasts longer than 10 minutes
- Bruise easily, with bruises that are raised and larger than a quarter
- Have someone in your family who has one or more of these symptoms
- Have someone in your family who has been diagnosed with a bleeding disorder, such as von Willebrand disease or hemophilia
How is von Willebrand disease diagnosed?
Some people may have VWD for years and never know it. That’s because they don’t have symptoms or their symptoms are so mild they’re easily overlooked.
Bleeding in people with VWD usually involves the mucous membranes of the body. Many people may not be diagnosed because their symptoms are subtle, ignored or believed to be caused by something else. Some of these symptoms include frequent nosebleeds, easy bruising, and prolonged bleeding after surgery or dental work.
A combination of blood tests is needed to diagnose VWD. In fact, these tests may need to be repeated several times before a definitive diagnosis can be made. That’s because VWF levels can change, depending on stress, infections or inflammation, exercise and time of day. Also, as people age, VWF can rise 1% - 2% annually. Other health conditions, such as hyperthyroidism, can affect VWF levels, too.