If you or a loved one are living with hemophilia, you’re likely familiar with the challenges of managing bleeding episodes. But did you know that some people with hemophilia also face a higher risk of developing blood clots? This condition, known as thrombophilia, can be surprising — and potentially serious — depending on where the clots form.

In this article, we’ll explore how hemophilia and thrombophilia can occur together, what causes thrombophilia, and what it means for people living with hemophilia.

What Is Thrombophilia?

Normally, clotting is a natural response to injury, helping to stop bleeding. However, in thrombophilia, clots can form even when they’re not needed, potentially blocking blood vessels. This can lead to serious health issues such as deep vein thrombosis (DVT, which blood clots form in deep veins in the arms or legs) and pulmonary embolism (a blood clot travels to the lungs).

Causes of Thrombophilia

Thrombophilia can result from:

• Genetic mutations inherited one’s parents
• Medications
• Other health conditions
• Lifestyle choices and habits

Thrombophilia can also be caused by a combination of these risk factors, leading to higher risk of dangerous clots.

Genetic causes of thrombophilia include factor V (5) Leiden thrombophilia and prothrombin thrombophilia. Each of these types affects around 1 percent to 5 percent of people. For people living with hemophilia, genetic mutations in the F2 and F5 genes are most common. These genes encode for clotting factors V and II (2), respectively. Note that Roman numerals are often used in discussions of clotting factors.

Medical conditions like cancer or autoimmune diseases (conditions in which the immune system attacks the body’s own tissues) may increase your risk of developing thrombophilia. Taking certain medications, like birth control pills, or staying very still for long periods of time, such as after a recent surgery, can also increase your risk.

Types of Blood Clots and Symptoms

Blood clots can form in blood vessels in different parts of the body. Understanding these clotting disorders can help you recognize symptoms and seek emergency medical care if you need it. Symptoms of blood clots depend on where they occur.

Deep Vein Thrombosis

Deep vein thrombosis refers to a blood clot in a deep vein, usually in the legs. DVT can cause a lot of pain and swelling. The affected area might feel warm to the touch, and the skin might become discolored. If not treated properly, DVT can lead to long-term pain and swelling, known as post-thrombotic syndrome. The most serious risk is pulmonary embolism.

Pulmonary Embolism

Pulmonary embolism occurs when a blood clot breaks loose from its original site (like a leg affected by DVT) and enters the lungs, blocking blood flow. This potentially life-threatening condition is a medical emergency that requires immediate treatment.

The most common symptom is sudden difficulty breathing. You might experience sharp chest pain that gets worse with deep breathing or coughing. Pulmonary embolism can strain the heart, and a severe blockage can lead to a heart attack or heart failure. In severe cases, pulmonary embolism can be fatal if not treated quickly.

Arterial Thrombosis

Arterial thrombosis happens when a blood clot forms in an artery, which carries blood from your heart to the rest of your body. This type of clot can block blood flow to vital organs, leading to serious consequences.

For example, a clot that blocks an artery in the brain can cause a stroke, leading to sudden weakness, speech difficulties, and other neurological issues. Clots in the arteries supplying blood to the heart can result in heart attacks. A clot that blocks an artery in the limbs can cause severe pain and numbness and, if left untreated, lead to tissue death and the need for amputation (the surgical removal of the affected limb).

Read more about the connection between hemophilia A and cardiovascular (heart and blood vessel) disease.

Hemophilia and Thrombophilia: How Are They Related?

At first glance, hemophilia and thrombophilia seem to be opposite conditions. However, people with hemophilia can sometimes also be at risk for blood clots. Multiple factors can cause people with hemophilia to develop thrombophilia.

For example, some hemophilia treatments involve infusing clotting factors to prevent bleeding. Using high doses of factor replacement therapy — for instance, to treat people with severe hemophilia — can raise the risk of clot formation. The drug emicizumab-kxwh (Hemlibra), which is used for severe hemophilia A, is also associated with an increased risk of clots.

Some people with hemophilia may have inherited genetic mutations that make them more likely to develop thrombophilia. For example, a family history of thrombophilia can raise the risk, even in people with hemophilia. The MTHFR gene is an inherited gene linked with a higher risk of blood clots. People with hemophilia A who have this gene may have milder bleeding episodes.

Prolonged periods of inactivity or immobilization (lack of movement) are often necessary during recovery from bleeding episodes, especially after joint bleeds. However, immobility can also increase the risk of blood clots.

Treating Blood Clots in People With Hemophilia

Although not very common or well understood, blood clots in people with hemophilia can happen. Some studies show that blood clots tend to develop in people who had recent surgery or replacement clotting factor therapy.

Treating blood clots in people with hemophilia can be difficult. Normally, doctors treat clots with blood thinners, but these drugs can make bleeding worse in people with hemophilia. Doctors must carefully weigh the pros and cons of treatment to avoid both excessive bleeding and clotting.

If a blood clot does form, your doctor will develop a treatment plan based on your specific needs. They’ll work with your health care team to balance the risks of bleeding and clotting.

Alternative therapies for managing blood clots may include compression stockings or mechanical devices. These measures can help prevent clots without increasing the risk of bleeding.

Understanding the relationship between hemophilia and thrombophilia is important for taking charge of your health. These conditions seem to be opposites, but they can occur together. If you have any concerns about blood clots, be sure to talk to your doctor. Together, you can create a plan to keep you healthy and safe.

Ways To Help Prevent Dangerous Blood Clots

Here are some steps you can take to minimize the risk of serious blood clots.

Regular Monitoring

Schedule regular checkups with your doctor or a hematology specialist (a doctor who specializes in blood disorders). They can run screening tests to check your clotting factor levels and overall health so that any issues are caught early.

Physical Activity

Take part in safe physical activities to promote good blood circulation and reduce the risk of clot formation. Exercises such as walking, swimming, and light cycling can help keep your blood flowing while protecting your joints.

It's important to avoid long periods of no movement, which can increase the risk of blood clots. If you need to sit for a long time, take breaks to stand up, stretch, and walk around. Even small movements can help keep your blood flowing properly and prevent clots from forming.

Hydration

Drinking plenty of water is important for keeping blood from becoming too thick and more likely to clot. Staying well hydrated helps maintain proper blood volume and flow, which is especially important during periods of rest or recovery. Aim to drink at least eight glasses of water a day or the amount your doctor recommends.

Talk With Others Who Understand

MyHemophiliaTeam is the social network for people with hemophilia and their loved ones. On MyHemophiliaTeam, more than 6,000 members come together to ask questions, give advice, and share their stories with others who understand life with hemophilia.

Have you experienced a blood clot while living with hemophilia? Share your thoughts in the comments below, or start a conversation by posting on your Activities page.