What Is Von Willebrand's Disease?
Von Willebrand’s disease is the most common inherited blood coagulation disorder, caused by a deficiency in a blood clotting factor known as von Willebrand’s factor. Von Willebrand’s factor promotes clotting in two ways: first, it is an essential component in the mechanism that causes platelets to gather and adhere to one another at the site of an injury; second, it acts as a carrier for Factor VIII (also known as antihemophilic factor), a crucial protein in the process of clot formation. A deficiency in von Willebrand’s factor thus results in uncontrolled bleeding due to inadequate platelet activity and decreased levels of active Factor VIII.
Von Willebrand’s disease affects both men and women alike (unlike hemophilia, which only leads to bleeding in men). The severity of symptoms varies widelymost cases are mild, with episodes of excessive bleeding presenting a risk only after surgery. Unlike hemophilia, most people with von Willebrand’s disease need not limit their level of physical activity. Treatment of bleeding episodes consists of transfusions of essential clotting factors from donated blood, or administration of a medication that stimulates the release of von Willebrand’s factor into the blood.
What Causes Von Willebrand's Disease?
- A genetic deficiency of von Willebrand’s factor, a clotting factor in the blood, causes von Willebrand’s disease. This condition is a genetically dominant trait, meaning it can be inherited by offspring if even only one parent carries the affected gene.
Symptoms of Von Willebrand's Disease
- Easy bruising
- Frequent nosebleeds
- Heavy bleeding from cuts, during menstrual periods and after surgery or tooth extraction
- Bleeding of the gums
- Blood in the urine or stool
- Swollen, painful joints (uncommon compared to hemophilia)
- Skin rash
Von Willebrand's Disease Prevention
- There is no way to prevent von Willebrand’s disease, although those with a family history of it may benefit from genetic counseling when considering having a child.
Diagnosis of Von Willebrand's Disease
- Patient history (including family history) and physical examination.
- Blood tests to measure bleeding time and blood levels of von Willebrand’s factor and Factor VIII.
- Platelet count, platelet aggregation test or a ristocetin cofactor test can be performed to diagnose von Willebrand disease.
How to Treat Von Willebrand's Disease
- Do not use medications such as aspirin that promote bleeding.
- Infusions of cryoprecipitate, a product containing concentrated clotting factors rich in von Willebrand’s factor and derived from donated blood, may be administered.
- Infusions of desmopressin (DDAVP), a medication that stimulates the release of von Willebrand’s factor and Factor VIII from blood vessel endothelia, may be administered to stop bleeding.
- For women with a severe form of von Willebrand’s disease, oral contraceptives may be prescribed to suppress unusually heavy menstrual bleeding.
- Patients may be advised to wear a medical bracelet identifying them as having a blood clotting disorder.
- Surgeons or dentists should be informed of the condition prior to surgery or tooth extraction, so that DDAVP or cryoprecipitate can be given and other precautions taken to prevent uncontrolled bleeding during and after the procedure.
When to Call a Doctor
- All blood relatives of someone with von Willebrand’s disease may want to be tested for the disorder.
- EMERGENCY Call an ambulance for any episode of prolonged, uncontrolled bleeding.
Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference
Simeon Margolis, M.D., Ph.D., Medical Editor
Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50
Updated by Remedy Health Media