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Diagnosis of von Willebrand disease

Is diagnosing von Willebrand disease easy?

No, diagnosing VWD is not easy. Many doctors are not familiar with it. As a result, VWD is often misdiagnosed.

For example:

• a person with a low platelet count because of Type 2B VWD could be misdiagnosed with leukemia

• a woman with heavy, prolonged menstrual bleeding because of VWD, who has not responded to hormone therapy, could be advised to have a hysterectomy.

For this reason, a person who thinks he/she has a bleeding problem should see a hematologist who specializes in bleeding disorders. Such a doctor can be found at a Hemophilia/Bleeding Disorder Treatment Centre. There, a diagnosis will be made by a specialist who is familiar with bleeding disorders and who has experience doing the proper blood tests.

Diagnosing VWD is difficult even for an experienced doctor. This is because the results of a person’s blood tests can vary from day to day. The test results can be normal, even when the person has VWD. There are a number of factors that cause the level of VWF to rise in the blood and appear to be normal. Some of them are:

• being pregnant
• breastfeeding
• normal hormonal changes during a woman’s monthly menstrual cycle
• being on the birth control pill (oral contraceptive)
• having an infection
• having recently undergone surgery
• having recently had a blood transfusion
• doing a lot of exercise.

VWF levels can change over time and tend to increase with age. In addition, people with blood group O have naturally lower levels of VWF. This, too, can make tests inconclusive.

Are routine blood tests a good way to diagnose von Willebrand disease?

No, they are not. Routine blood tests will often give normal results in people who have von Willebrand disease. With this condition:

• the prothrombin time is always normal
• the partial thromboplastin time is almost always normal and
• the bleeding time is often normal.

In fact, the test for bleeding time is the least accurate of all tests used.

What tests are reliable in diagnosing von Willebrand disease?

A doctor who suspects VWD will first take a complete family history. He/she will then do a number of blood tests to find out:

• if the person has VWD and
• what type of VWD the person has.

The tests may include ...


Bleeding time
This measures the length of time it takes for a simple cut to stop bleeding
Factor VIII: C
This measures the amount of factor VIII clotting activity.
VWF: antigen
This measures the amount of von Willebrand factor.
Ristocetin cofactor activity
This measures how well the VWF works.
VWF multimers
This examines the structure of the VWF.
Platelet function tests
These measure how well the platelets work.


How long does it take to get the results?

Some of the tests must be done in a specialized laboratory. Therefore, it may be several weeks before test results come back.

If all the tests are normal the first time, should a person be re-tested?

Sometimes. This is because a person’s test results can be normal one day and abnormal a month later.

Even if all the tests are normal the first time, and the doctor does not believe there is a bleeding disorder, a person who believes he or she has a bleeding problem should discuss the need for being re-tested with his/her physician.

If the health care institution does not have experience with von Willebrand disease, the person should ask to be referred to a hematologist experienced with bleeding disorders or to a Hemophilia/Bleeding Disorder Treatment Centre.

Unfortunately, many people in the past have accepted their doctors' diagnoses that all was normal. They had to live with the bleeding problems caused by VWD when they could have received proper treatment.

What reactions do people have when they are diagnosed with von Willebrand disease?

Many people feel relief that the problems they have experienced over many years have finally been diagnosed. With diagnosis comes the possibility of effective treatment.

Others feel worried or scared about being diagnosed with a lifelong condition, especially one with such an impressive name. Over time, however, these fears can change into feelings of empowerment as more is learned about the disease, and the person takes more control over it.

It is important to get support from others at this time. Medical people, friends and family members can help a person through this difficult period. Contact with people who are already living with VWD can be of special comfort in allaying fears. Get in touch with the local chapter of the Canadian Hemophilia Society for this kind of help.

Should a person inform other family members of the diagnosis?

Yes. Other family members may also have symptoms of VWD and may not have been diagnosed.