Learn more about your von Willebrand disease
For more information about von Willebrand disease, visit these websites, or read these publications: the National Heart, Lung and Blood Institute website (http://www.nhlbi.nih.gov/health/health-topics/topics/vwd/, https://www.nhlbi.nih.gov/health/health-topics/topics/vwd/signs, https://www.nhlbi.nih.gov/health/health-topics/topics/vwd/diagnosis), the Hemophilia of Georgia website (http://www.hog.org/handbook/section/2/the-inheritance of-von-willebrand-disease), the National Hemophilia Foundation website (https://www.hemophilia.org/Bleeding-Disorders/Types-of-Bleeding-Disorders/Von-Willebrand-Disease), and Castaman G. Blood Transfus. 2011;9:s9-s13.
What is von Willebrand disease?
Von Willebrand disease (VWD) is an inherited bleeding disorder. People with VWD have a deficiency in a protein called von Willebrand factor (VWF). VWF is a glue-like protein that helps cells in your blood, called platelets, clump together and form a plug that prevents blood loss following an injury. People with VWD cannot make this plug because their body does not make enough VWF, or what they do make is not effective. VWD is the most common bleeding disorder. Up to 1% of the population may have VWD
VWD is the most common bleeding disorder in the United States.
What causes von Willebrand disease?
VWD is caused by a problem in one of the genes that tells the body to make VWF. Unlike hemophilia, which mainly affects males, VWD affects both men and women equally. A man or woman with VWD has a 50% chance of passing the disease on to their child.
What are the types of von Willebrand disease?
There are 3 main types of VWD and several subtypes. The 3 main types are:
- VWD type 1: The most common form. A person with type 1 has about 20% to 50% of normal levels of VWF. Levels of the blood clotting factor VIII might also be reduced
- VWD type 2: People with type 2 produce enough VWF, but the protein is defective and affects the way that FVIII binds, as well as the way that platelets clump together
- VWD type 3: The least common but the most severe form of VWD. People with type 3 might have a total absence of VWF, and factor VIII levels are often very low
In people with VWD types 2 and 3, bleeding episodes may be severe and potentially life-threatening.
What are signs and symptoms of von Willebrand disease?
- Bruising easily
- Bleeding gums
- Frequent nosebleeds
- Excessive bleeding after losing a tooth or oral surgery
- Women can have increased menstrual bleeding
- Severe internal or joint bleeding (with type 3 VWD)
How is von Willebrand disease diagnosed?
- Appearance of the above symptoms
- Diagnosing VWD can be difficult. Laboratory blood tests can be performed to determine the amount, structure, and function of VWF
- A family history of VWD. Because VWD is an inherited condition, a child of people who have the VWD gene needs to be tested
What happens in von Willebrand disease blood clotting?
There are 4 stages in VWD blood clotting:
- The blood vessel constricts, reducing blood flow through the wounded area
- The body does not produce enough VWF, so platelets don't stick together and the platelet plug does not form as effectively. Bleeding continues
- People with VWD often do not produce enough clotting factor VIII either. Factor VIII is crucial in forming the mesh that holds the platelet plug in place. Without enough factor VIII, the mesh does not as effectively hold the platelet plug in place
- When a person with VWD uses plasma-derived FVIII/VWF complex, enough VWF and factor VIII are temporarily added to the blood, allowing platelets to effectively form a platelet plug and blood to form the mesh that holds the platelet plug together; bleeding can be stopped or prevented