To read our primer on Hemophilia, click here.
Pop quiz, Patient Worthy-style: What is von Willebrand Disease?
And no Googling!
For those who were familiar, A+! And for the rest who weren’t, this one is for you.
Von Willebrand Disease (vWD) is the most common type of bleeding disorder, affecting about 1% of the world’s population.
That’s almost 75 MILLION people! That may seem disturbingly high for a rare disease, but the fact is that because symptoms can be mild, many with vWD are not diagnosed. In fact, research suggests as many as 9 out of 10 people living with vWD have not been diagnosed.
So let’s take a basic but thoughtful dive into this bleeding disorder.
Unlike hemophilia, it affects men and women equally. The name comes from the von Willebrand factor (vWF), a blood glycoprotein that is integral in hemostasis – the process that’s basically in charge of blood clotting. VWF is the protein that makes platelets stick together to form a platelet plug.
Before we go any further, let’s just take a moment to marvel at the beautiful complexity that is the human body.
Every organ and organelle plays a role in how our body works. Complicated bioengineering is happening everyday inside of us! I can’t be the only one who agrees, right?
I’m sure Dr. Erik von Willebrand would agree with me, who was credited with discovering the bleeding disorder itself, hence the disorder’s name.
Those with vWD have issues with blood clotting because (as you might have pieced it together), their vWF is not doing what it’s supposed to (i.e. clotting blood). Specifically, those platelets aren’t sticking to make that plug necessary for the blood to clot – although each type of vWD accounts for exactly why the vWF is not working, and depending on the type, it’s either a quantitative issue (the amount of vWF is compromised) or a qualitative issue (the quality of vWF is compromised).
Phew, science! Okay, now that we got some technical info, what are the symptoms? That depends on the type of vWD.
- Type 1 vWD occurs when vWF levels are lower than normal. This is the most common type of vWD (accounts for 60-80% of vWD diagnoses) and has the mildest symptoms – and sometimes can even be asymptomatic. In fact, those with Type 1 often get diagnosed only after undergoing medical procedures (even minor ones). Symptoms may include:
- Bruising
- Nosebleeds
- Prolonged bleeding from the gums after a dental procedure
- Heavy or prolonged menstrual bleeding in women
- Blood in your stools from bleeding in your intestines or stomach
- Type 2 vWD is when the quality of vWF is defective, i.e. it’s just not doing what it’s supposed to be doing in a significant way, and it accounts for 15-30% of diagnosed cases of vWD. There are four subtypes of Type 2 vWD (which you can read about more here) but they all have to do with the qualitative defect of vWF. And while Type 1 and Type 2 share a lot of the symptoms, the symptoms of Type 2 have a higher intensity or frequency than those of Type 1.
- Lastly, Type 3 is the most severe form of vWD and accounts for 5-10% of diagnoses. In Type 3 vWD, there is a complete absence of vWF production, or is virtually undetectable. This means the coagulation process in blood clotting is severely compromised. The symptoms are similar to the other types, but much more severe, frequent, and prolonged – and can include internal bleeding, manifesting in blood found in urine or stool and in organs like the kidneys, bladder, intestines, or stomach.
So not all vWD is created equal – each type not only has differences in symptoms, but also in causes (qualitative or quantitative vWF issues) – which is important when considering how patients are diagnosed and how researches look for treatment and cures.
