Hemophilia and von Willebrand disease (VWD) are blood clotting disorders that raise your risk of bleeding. While they can cause similar symptoms, there are many key differences between these two diseases.

In this article, we’ll discuss VWD and how it differs from hemophilia. We’ll cover how they develop, what symptoms they cause, and how they’re treated. To learn more about hemophilia and VWD, talk to your hematologist (blood specialist).

VWD and Hemophilia Affect Different Clotting Proteins

VWD and hemophilia are both bleeding disorders — but they affect different proteins that help make blood clots.

VWD Affects Von Willebrand Factor

VWD develops when your body doesn’t make enough of a protein called von Willebrand factor (VWF). This protein is found in:

• Platelets (specialized blood cell fragments)
• Plasma (the liquid part of the blood)
• Blood vessel walls

VWF helps platelets stick together to form blood clots. Without enough of this protein in your platelets, your blood can’t make clots as well as it should. This is why people with VWD bleed more easily.

There are three types of VWD, which are categorized by how much VWF you make. Type 1 VWD affects people who have low VWF levels. This is the most common type of VWD, affecting 60 percent to 80 percent of those with the disease. The VWF protein still works as it should in those with type 1 VWD.

In type 2 VWD, there isn’t enough VWF protein available, and it doesn’t work properly. This is the second most common type of VWD. According to Cleveland Clinic, between 15 percent and 30 percent of people with VWD have this type.

Type 3 VWD is the most severe because it causes the lowest levels of VWF. Around 5 percent to 10 percent of people with VWD have type 3. Due to very low levels of VWF, a person with this type is at risk of severe bleeding problems.

Hemophilia Affects Clotting Factors VIII, IX, and XI

Hemophilia occurs when people make very little or no clotting proteins or clotting factors. These proteins normally work together with platelets to form blood clots. Without enough clotting factors, you’re at risk of serious bleeding episodes.

There are three types of hemophilia, and they’re each associated with low levels of a particular clotting factor protein. (You will usually see Roman numerals in any discussion of clotting factors.)

• Hemophilia A — Factor VIII (8)
• Hemophilia B — Factor IX (9)
• Hemophilia C — Factor XI (11)

VWD and Hemophilia Are Inherited in Different Ways

VWD and hemophilia are both genetic bleeding disorders. This means they’re passed down from parents to their children. If you have VWD or hemophilia, you have mutations (changes) in your blood clotting factor genes. People with a family history of these disorders inherit these mutations in different ways. To better understand how VWD and hemophilia are inherited, it helps to learn about chromosomes.

Humans have 23 pairs of chromosomes made of DNA. This means you inherit one set from each parent, and you have two copies of every gene. One pair are the sex chromosomes — humans can have X and Y chromosomes. Females have two X chromosomes, and males have an X and a Y chromosome. The other 22 pairs are known as autosomal chromosomes.

VWD Is an Autosomal Disease

VWD is an autosomal disease, meaning that the VWF gene is found on an autosomal chromosome. In the majority of type 1 and type 2 cases, VWD is autosomal dominant. This means you need only one mutated copy from one parent to develop VWD. If you have a parent with VWD, you have a 50 percent chance of developing it yourself.

In rarer cases, VWD can be autosomal recessive. This means you need mutations in both copies of the VWF gene — one from each parent — to develop VWD. Type 3 VWD is autosomal recessive.

Hemophilia Is an X-Linked Disease

Hemophilia A and B are referred to as “X-linked recessive diseases” because clotting factor genes are found on the X chromosome. Males are much more likely to develop hemophilia because they inherit only one X chromosome, according to Cleveland Clinic. Females inherit two X chromosomes, so they can compensate with a healthy clotting factor gene on the other chromosome. Unlike hemophilia, VWD affects men and women equally, according to the Centers for Disease Control and Prevention (CDC) . Hemophilia C, although very rare, is an autosomal recessive condition.

People With VWD or Hemophilia May Experience Different Symptoms

VWD and hemophilia both cause excessive bleeding. However, there are some key differences in the symptoms people experience.

Most people with VWD don’t experience any symptoms or have mild signs of disease. If you have type 2 or 3 VWD, you may have:

• Frequent nosebleeds that last at least 10 minutes
• Excessive bleeding after surgeries, injuries, cuts, or dental work
• Anemia (decrease in the number of red blood cells) due to iron deficiency
• Large bruises that form bumps underneath the skin
• Heavy menstrual bleeding (periods) that causes you to change a pad or tampon at least once an hour
• Blood in your urine and stool

Hemophilia also causes many of these symptoms. However, people with hemophilia are also more likely to experience internal bleeding. You may notice joint swelling, pain, or tightness. Commonly affected joints include the shoulders, hips, ankles, and knees.

In rare cases, those with severe hemophilia can develop brain bleeds. Signs of a brain bleed include double vision, severe headaches that don’t go away, and decreased level of consciousness. If you have hemophilia and develop any of these symptoms, get medical attention immediately.

VWD Symptoms Can Develop Later in Life

In most cases, bleeding disorders are diagnosed early in a person’s life. Children with hemophilia are usually diagnosed when they’re 12 to 18 months old. This is when easy bruising starts and points to a diagnosis. VWD is usually diagnosed later in childhood, especially in people with mild disease. One study found that three-quarters of males with VWD were diagnosed by age 10, and half of females were diagnosed after age 12. Females with VWD are usually diagnosed after menarche (onset of their menstrual periods), as this is the time when they will notice excessive bleeding.

Adults with certain health conditions can also develop a form of VWD later in life. This is known as acquired von Willebrand syndrome. It’s usually diagnosed in people with immune system or blood cell problems.

Doctors Diagnose VWD and Hemophilia With Blood Tests

If you’re experiencing symptoms of VWD or hemophilia, your doctor will likely order blood tests to make a diagnosis. They’ll run a complete blood count (CBC), which measures levels of several blood cells. Prothrombin time (PT) and activated partial thromboplastin time (APTT) tests also measure how quickly your blood forms clots.

Specific tests also measure your clotting factor levels. If your doctor thinks you have VWD, they’ll check the amount of VWF in your blood. They can also determine the shape of the VWF protein to make sure it works properly. A ristocetin cofactor test checks VWF protein activity to see if it is functioning properly. To check for hemophilia, doctors measure levels of factors VIII, IX, and XI.

Treatment Options for VWD and Hemophilia Differ

Your VWD or hemophilia treatment depends on how severe your symptoms are. Most people with mild disease don’t need treatment.

The most common VWD treatment is desmopressin (DDAVP). This hormone helps the body make more VWF to form blood clots.

Doctors can also treat bleeding disorders by supplying the missing clotting factors — known as replacement therapy. The clotting factors are made in a lab or are collected from donors who give their plasma. Replacement therapy is usually given to people with severe VWD or hemophilia. It’s also given before surgeries to prevent bleeding. Those with VWD receive VWF treatments, and those with hemophilia get factor VIII, IX, or XI treatments.

Taking birth control pills can help control menstrual bleeding. Most types of birth control have estrogen — a hormone that raises VWF levels in the body.

Talk to Your Physician About Hemophilia

If you have more questions about hemophilia and VWD, talk to your doctor. They can explain the differences and answer questions you have about characteristics of your hemophilia.

Talk With Others Who Understand

On MyHemophiliaTeam, the social network for people with hemophilia and their loved ones, more than 6,500 members come together to ask questions, give advice, and share their stories with others who understand life with hemophilia.

Are you living with hemophilia or von Willebrand disease? Do you have any other questions about the differences between these two blood clotting disorders? Share them in the comments below, or start a conversation by posting on your Activities page.