Diagnosing VWD

According to the Centers for Disease Control and Prevention (CDC), VWD is the most common bleeding disorder, affecting up to 1% of the US population. It is equally likely to affect men and women, but women are more likely to experience symptoms due to their reproductive processes.1

The disease is characterized by easy bruising and excessive mucosal bleeding, such as heavy menstrual periods and bleeding from the mouth or nose. VWD is caused by a deficiency or abnormality of von Willebrand factor (VWF), a protein in the blood that is instrumental in promoting platelet adhesion to areas of blood vessel injury.

To diagnose VWD, your doctor should consider:

  • Your health history — When did you first start bleeding excessively? How long does the bleeding last? When does the bleeding start and where and how often do you bleed?
  • Family history — VWD is an inherited bleeding disorder,* so your doctor may ask about bleeding patterns of family members
  • Lab tests — Blood samples may show if you have VWD and if so, what type

*In most cases, a person inherits VWD from a parent; in rare cases, VWD can be acquired.2

VWD can be difficult to diagnose. Here’s why:

Symptoms of VWD can be very mild, even unnoticeable.2

  • Mild symptoms of VWD may be mistaken for other illnesses
  • People with VWD may not even suspect they have the disorder and may never get tested
  • Some find out they have VWD only after they’ve had heavy bleeding following an accident or surgery
  • In women, menorrhagia (heavy menstrual bleeding) may be the only manifestation of VWD

The amount of von Willebrand factor in someone’s blood can vary at different times.

  • Certain situations or conditions (stress, pregnancy, infection, etc.) can cause the amount of VWF to temporarily increase,3 making it hard for doctors to make a specific diagnosis
  • This means blood tests would need to be taken more than once

Testing for VWD is complicated

  • Testing for VWD involves many different kinds of blood tests
  • If you believe you have VWD, it is important to go to a hemophilia treatment center or to a hematologist (a doctor who specializes in testing for and treating bleeding disorders)

Should you get tested for VWD?

If you have mild symptoms, you should get tested for VWD. The signs and symptoms of VWD are:

  • Easy bruising
  • Frequent or prolonged nosebleeds
  • Menorrhagia (heavy or prolonged menstrual periods)
  • Prolonged bleeding following injury, childbirth, or surgery
  • Prolonged bleeding during dental procedures

Why is it important to get tested? If you are in an accident or you need surgery, you may experience heavy and prolonged bleeding. To give you the proper treatment, your healthcare provider would need to know what’s causing the extra bleeding—VWD or the injury itself.

In order to diagnose VWD and select the appropriate therapeutic option, your doctor must determine the specific disease type and subtype. Doing so could require several specific blood tests, which may include one or more of the following:

  • VWF activity (VWF:ristocetin cofactor, or VWF:Rco) – provides a measurement of VWF function
  • VWF multimer assay – analyzes the quality and provides a measurement of VWF multimers; this is an essential test for determining subtype.
  • FVIII clotting activity (FVIII:C) – determines the degree of FVIII activity.
  • VWF antigen (VWF:Ag) – measures the quantity of VWF.
  • Ristocetin-induced platelet aggregation (RIPA) – provides a measurement of VWF function.
  • Platelet function analyzer 100 (PFA-100) – identifies the presence of VWD through primary hemostasis simulation.

Repeated laboratory tests may be required to confirm or rule out a diagnosis of VWD. This is because VWF levels can fluctuate due to exercise, stress, recent surgery, infection, hormone therapy, medications, and pregnancy, childbirth, and breast feeding. The patient’s blood type can also complicate diagnosis of VWD as blood group O individuals have plasma levels of VWF 20% to 25% lower than non-O individuals.3

Important Safety Information

Antihemophilic Factor/von Willebrand Factor Complex (Human), Humate-P® is approved to treat and prevent bleeding in adult patients with hemophilia A (classical hemophilia). Humate-P also treats spontaneous or trauma-induced bleeding episodes in adults and children with von Willebrand disease (VWD) and prevents excessive bleeding during and after surgery in patients with mild, moderate or severe VWD. Humate-P is not known to prevent spontaneous bleeding episodes.

Do not take Humate-P if you have had extreme sensitivity or an allergic response to antihemophilic or von Willebrand factor preparations. Your doctor will monitor you for events related to abnormal blood clotting.

Humate-P is made from human blood and could contain infectious agents. The risk that these agents may transmit disease cannot be completely eliminated, but has been reduced by screening plasma donors and testing donated plasma for certain viruses, and by inactivating and/or removing viruses during manufacturing.

In studies, more than 5% of patients reported the following adverse reactions to Humate-P: allergic/anaphylactic reactions, including hives, chest tightness, rash, itching, and swelling. The most common adverse reactions after surgery were bleeding at the wound or infusion site, and nosebleeds.

Please see full prescribing information.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

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© CSL Behring 2019. The product information on this site is intended for US residents only. HUM / 10-11-0010(1) 8/2015


  1. Centers for Disease Control and Prevention (CDC). Facts about von Willebrand disease. http://www.cdc.gov/ncbddd/vwd/facts.html Published March 20, 2015. Accessed April 27, 2015.
  2. National Heart, Lung, and Blood Institute. The diagnosis, evaluation and management of von Willebrand Disease. 2007. NIH Publication No. 08-5832. Available at www.nhlbi.nih.gov/guidelines/vwd/. Accessed June 16, 2010.