Thrombophilia (Clotting Disorders)

What is thrombophilia?

Thrombophilia, or clotting disorders, are conditions that make the blood more likely to form blood clots. Normally, blood clots are helpful because they help stop bleeding after an injury. In thrombophilia, there is an increased risk of blood clots forming when they are not needed. This can cause serious health problems that may be life-threatening.

Blood flows throughout the body in blood vessels called arteries and veins. If a person gets a cut or wound, a clot forms at the site of the injury to help stop bleeding. A blood clot is made of blood cells and proteins that stick together to form a mass.

A blood clot (thrombus) can sometimes form inside a blood vessel and block the flow of blood. This is called thrombosis. A clot can also break off and travel through the blood vessel to the lungs or brain (embolism).

Thrombophilia can develop later in life (acquired) or can be passed down in families (inherited). People with thrombophilia may need blood-thinning medicines and other treatments to manage the condition.  

Symptoms of clotting disorders

Some people with thrombophilia may show no symptoms until a blood clot forms.

Signs and symptoms of a blood clot depend on where the clot is in the body.

Deep vein thrombosis (DVT): If the blood clot is in a deep vein of a leg or arm, signs and symptoms may include:

• Pain or tenderness
• Swelling
• Warmth
• Redness or discoloration of the skin

Pulmonary embolism: If the blood clot travels to the lungs, signs and symptoms may include:

• Chest pain
• Shortness of breath or difficulty breathing
• Rapid heartbeat or heart racing
• Unexplained cough or coughing up blood

Stroke: If the blood clot travels to the brain, signs and symptoms may include:

• Numbness or weakness in the face, arms, or legs on 1 side of the body
• Sudden, strong headache
• Dizziness or balance problems
• Vision changes
• Trouble speaking

Blood clots can also occur in other parts of the body, such as the abdomen, liver, and kidneys.

A blood clot is a medical emergency. Seek medical help right away if your child has any of these signs or symptoms.

Causes of thrombophilia

There are 2 main types of clotting disorders:

• Acquired thrombophilia: clotting disorder that develops later in life
• Inherited thrombophilia: clotting disorder that you are born with that is passed down through families

Types of inherited thrombophilia

Inherited or genetic thrombophilia happens when a gene change (mutation) increases the risk of blood clots. Thrombophilia can be caused by different gene mutations, such as:

Factor 5 (V) Leiden: thrombophilia caused by a mutation in the Factor 5 (F5) Leiden gene. This gene makes a protein called Factor 5, which is used by the body as part of blood clotting. People with this mutation have an increased risk for deep vein thrombosis (DVT) and pulmonary embolism (PE). This is the most common inherited risk factor for blood clots and is found in 5% (5 in 100) of people of European origin.

Prothrombin gene mutation 20210 (Factor 2): thrombophilia caused by a mutation in the Prothrombin Factor 2 (F2) gene. This leads to higher levels of prothrombin protein, which increases the risk of blood clots, including deep vein thrombosis (DVT) and pulmonary embolism (PE).

Protein C deficiency: thrombophilia caused by a mutation in the PRONC gene. People with this mutation make less of a substance called protein C, which helps control blood clotting. A lack of protein C increases the risk of deep vein thrombosis (DVT), pulmonary embolism (PE), and blood clots during pregnancy. This condition is rare, affecting only about 1 in 20,000 people.

Protein S deficiency: thrombophilia caused by a mutation in the PROS1 gene. People with this mutation make less of a substance called protein S, which helps control blood clotting. Protein S deficiency increases the risk of deep vein thrombosis (DVT), pulmonary embolism (PE), and blood clots during pregnancy. Inherited protein S deficiency is rare, affecting only about 1 in 20,000 people. A more common form of acquired Protein S deficiency can be caused by liver or kidney problems or a lack of Vitamin K in the body (Vitamin K deficiency).

Dysfibrinogenemia, which can be either inherited or acquired. Inherited dysfibrinogenemia is caused by a gene mutation for fibrinogen (Factor 1), a substance that helps the blood clot. This mutation increases the risk for blood clots and abnormal bleeding. People can also develop acquired dysfibrinogenemia, which can happen due to cancer treatments, liver disease, or an autoimmune disease.

Risk factors for thrombophilia

Certain factors can increase the risk of a blood clot, whether thrombophilia is acquired or inherited. These include:

• Recent surgery or injury
• Long periods of inactivity or bedrest
• Having certain medical devices, such as a central venous catheter (central line) or shunt
• Certain illnesses or medical conditions, such as chronic inflammatory diseases, cancer, blood disorders, heart failure, or COVID-19
• Medicines such as hormone therapy or birth control pills
• Obesity
• Pregnancy
• Smoking
• Family history of blood clots
• Inherited disorders that cause blood clots

Diagnosis of thrombophilia

Thrombophilia is diagnosed based on your child’s medical history, physical exam, and lab tests. Your care team may ask about past blood clots and if there is a family history of clotting events.

Blood tests and genetic testing may be done to look for gene changes that increase the risk of clotting.

If your care team suspects a current blood clot, they may do other tests:

• Blood tests such as:
  • Complete blood count test
  • Coagulation panel to measure things in the blood and to see how fast the blood clots
  • D-dimer test (to measure a substance that breaks down clots in the blood)
• Imaging tests to find blood clots, such as ultrasound, transcranial doppler ultrasound, CT scans, X-ray, Ventilation-perfusion scan (VQ Scan), pulmonary angiogram
• Pulse oximetry to measure the oxygen levels in the blood if a blood clot in the lung is suspected
• Echo-cardiogram to test heart function

If your child has a blood clot, it is important to seek medical care to get the clot treated early and prevent serious medical problems.

Treatment of thrombophilia

Management of thrombophilia often includes medicines to prevent blood clots, medical monitoring, and lifestyle changes.

The type of treatment depends on the type and severity of the condition. Some people need monitoring and might only need medicine or other treatment in special situations, such as after surgery or during pregnancy.

Anticoagulant medicines (blood thinners), such as heparin and warfarin, may be used to help prevent blood clots in some cases.

Talk to your care team about how to lower your child’s risk of blood clots. Healthy habits like being physically active, staying at a healthy weight, and not smoking are especially important.

If your child has a blood clot, seek medical care right away. Treatment will depend on the cause and where the clot is located. Treatment for a blood clot may include:

• Medicines such as blood thinners (anticoagulants) to keep the clot from getting bigger or medicines to dissolve blood clots (thrombolytics).
• Surgery to remove the clot (thrombolysis or thrombectomy). This can be done using a small tube (catheter) inserted into the blood vessel or by open surgery in some cases.
• Inferior vena cava filter (IVC filter) placed in a large vein in the body to filter out blood clots, so they do not go to the lungs. This is not common and is only used in certain cases.

Carefully follow your care team’s instructions for medicines. Your child may need monitoring and regular blood tests to make sure their medicine is at the correct dose. If your child takes blood-thinning medicines, watch for signs of unusual bleeding or bruising.

Tell all health care providers about your child’s condition and their risk of blood clots, especially before surgery or dental procedures. Let all providers know about medicines and supplements that your child takes. These may affect how their blood clots.

Living with thrombophilia

If your child has thrombophilia, lifestyle habits can help support healthy blood flow and lower the risk of blood clot formation:

• Be active: Help your child stay active by moving often and exercising regularly to keep blood flowing well.
• Avoid long periods of sitting: During long trips or other periods of inactivity, have your child stand up and stretch every 1-2 hours.
• Stay hydrated: Make sure your child drinks plenty of water to keep blood flowing more easily.
• Maintain a healthy weight: Encourage healthy eating and physical activity to help your child maintain a healthy weight.
• Avoid risky behaviors: Remind your child not to smoke or vape, because it increases the risk of clots.
• Plan ahead for medical procedures: Ask your care team if any extra steps are needed during times when the risk of them getting a clot is higher, such as after surgery, injury, or illness.
• Take medicines as prescribed: If your child takes a blood-thinning medicine, make sure they take it exactly as prescribed and report any unusual bleeding or bruising.
• Wear a medical alert tag: Talk to your care team about a medical alert tag for your child especially if they take blood-thinning medicines or have a high risk for clots.

When to call your care team

Contact your care team if your child has any of the following signs or symptoms:

• Shortness of breath or trouble breathing
• Pain, warmth, or swelling in an arm or leg
• Sudden, severe headache
• Numbness or weakness, especially on 1 side of the body
• Sudden vision changes
• Confusion or Problems speaking

A blood clot is a medical emergency. Seek medical help right away if your child has any of these signs or symptoms.

Questions to ask your care team

• Which thrombophilia disorder does my child have, and what does it mean?
• Is my child’s thrombophilia inherited or acquired?
• What treatment or monitoring does my child need?
• Are there lifestyle changes that can help lower my child’s risk of blood clots?
• Should family members be tested for thrombophilia?
• What signs of a blood clot should I look for?
• When should I call the doctor, and when should I go to the emergency room?

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