Our Thrombosis Experts Answer Your Clotting Questions

Why should people with a clotting disorder go to a hemophilia treatment center?

Hemophilia treatment centers provide comprehensive care for people with bleeding and clotting disorders. Hemophilia treatment centers are staffed by a range of healthcare providers, including hematologists, nurses, nutritionists, genetic counselors, physical therapists, and social workers, who work as a team to address the needs of persons with clotting disorders.

Hemophilia treatment centers providers help persons with clotting disorders better understand and manage their medical condition.

Do people with a clotting disorder need to see a specialist?

Many primary care providers manage patients with blood clots. However, if a patient has or has had a blood clot, it is recommended that they also are seen by a hematologist who specializes in the area of bleeding and clotting disorders.

Hematologists are an essential part of the IHTC care team. A hematologist accurately identifies and diagnoses clotting abnormalities that may contribute to the development of a clot. Accurate diagnosis is essential to the health of patients and families.

Hematologists have extensive experience in the management of anticoagulation. Appropriate choice of an anticoagulant and the level and length of anticoagulation are based on each patient’s diagnosis and individual circumstances, including the location and size of the clot, the presence of factors that can “trigger” a blood clot, patient age, and family history.

If a patient has been diagnosed with factor V Leiden, should family members be tested, even if they have not personally experienced a blood clot?

If a patient has been diagnosed with an inherited clotting disorder such as factor V Leiden, his or her family members might also be affected and should be tested. Testing of family members allows for appropriate preventive healthcare management and for individuals to make informed decisions about their healthcare.

This information may be helpful in medical decision making in certain circumstances, such as pregnancy, type of birth control utilized, and surgery. Family members who might be at risk for these conditions may visit a hematologist to have this testing performed.

The IHTC also has a genetic counselor who can explain this testing and the test results to patients and their families.

What can the IHTC do for you?

The IHTC has an expert medical team with years of experience in the diagnosis of clotting disorders and anticoagulation management. The IHTC provides genetic counseling services for individuals with clotting disorders and their families

The IHTC’s registered dietitian provides information and advice on diet-related issues that affect anticoagulant medications, particularly warfarin. Take a look at our warfarin interactions guide for useful nutritional information and important dietary tips for patients on a warfarin treatment plan.

What is a clotting disorder (thrombophilia)?

Thrombophilia describes a group of clotting disorders in which there is an increased tendency for excessive blood clotting. Clotting disorders can be due to inherited genetic abnormalities that are associated with a life-long increased tendency to clot.

Learn more about inherited causes of clotting disorders

Clotting disorders may also be associated with acquired conditions such as lupus anticoagulants or an antiphospholipid antibody, which can occur in persons either with or without systemic lupus erythematosus.

Learn more about acquired causes of clotting disorders

Who can have a clotting disorder?

Clotting disorders affect a large number of men and women throughout the world. People who experience episodes of blood clots, either as a single event or as repeated events, may have a clotting disorder.

Both children and adults can have a clotting disorder. Blood clots are more commonly diagnosed during the teen and adult years due to normal changes in the blood that occur with growth and aging. Women who have a clotting disorder can have clotting problems during pregnancy and delivery and with the use of birth control pills or hormone replacement therapy.

Factor V Leiden affects approximately 5-10% of white Americans of European descent. Some people may have an identifiable clotting disorder, such as factor V Leiden, yet do not experience a blood clot.

Are all clotting problems inherited?

Not all clotting disorders are inherited. Clotting disorders can also be acquired, meaning they may develop at any time without an underlying genetic cause. Some acquired clotting disorders are related to disease states that can be controlled or reversed, such as:

  • Diabetes

  • High blood pressure

  • Pancreatitis

  • Inflammatory bowel disease

  • Obesity

Healthcare providers are able to discover the cause of excessive clotting in some patients and families, but not in all cases. Further research is needed to understand why some individuals without an identifiable cause have clotting problems.

What is thrombosis (blood clot formation)?

Thrombosis is the formation of a blood clot inside a blood vessel that blocks the normal flow of blood through the bloodstream. Blood clots may occur in either veins (blood vessels that deliver blood from the tissues to the heart) or arteries (vessels that deliver blood from the heart to the tissues).

A blood clot can reduce or completely shut off blood flow and oxygen to body tissues, resulting in pain, tissue damage and, in some cases, death.

What is an embolism?

An embolism occurs when part of a blood clot breaks off and travels in the bloodstream to another part of the body, where it may block blood flow in the affected vein or artery.

Are there different types of blood clots in veins?

Yes. The most common types of clots in veins are deep vein thrombosis and pulmonary embolism.

deep vein thrombosis is the formation of a blood clot within one of the large deep veins of the body. It usually occurs in the deep veins of the legs or hips, although it can happen in other areas as well.

Learn more about the signs of deep vein thrombosis

A pulmonary embolism occurs when a part of a deep vein clot breaks off and flows in the bloodstream to the lungs. In the lungs, the embolized blood clot can block the blood vessels and reduce or prevent the flow of blood to the lungs. Pulmonary embolism is the most serious complication of thrombosis and can result in death if not treated.

Learn more about the signs of pulmonary embolism

How common are blood clots?

Deep vein thrombosis and pulmonary embolism are very common medical problems and are a significant cause of illness and death in the United States.

According to the CDC, an estimated 600,000–1,000,000 people in the United States die from a deep vein thrombosis or pulmonary embolism each year. Of the people who have experienced a deep vein thrombosis, nearly one third develop post-thrombotic syndrome, a long-term condition that can cause disabilities.

Deep vein thrombosis is preventable and treatable if diagnosed correctly and early.

People with post-thrombotic syndrome may have swelling, pain, discoloration, and scaling of the affected limb. For some people, deep vein thrombosis may become a chronic illness. Approximately 30% of individuals who experience a deep vein thrombosis are at risk for having another episode.


What causes blood clots?

Blood clots are the result of three principal factors:

  • Pooling of blood in the deep veins

  • Damage to blood vessels

  • Increase in the activity of the components in the blood that are part of the normal clotting process (this increased activity leads to a super-clotting state)

Several factors can help cause the conditions listed above, thereby increasing the risk of a blood clot:

  • Inherited abnormalities that cause an increased tendency to clot

  • Surgical procedure

  • Sitting or lying down for long periods (more than 4 hours) - for example, after surgery or on long plane or car rides (this lack of movement reduces blood flow in the legs by 50%)

  • Major injury

  • Increasing age

  • Cancer

  • Heart failure

  • Pregnancy

  • Use of hormone therapy such as birth control pills or hormone replacement therapy

  • Having a history of deep vein thrombosis


Other risk factors for blood clots may include:

  • Diabetes, which leads to damage of the blood vessels

  • Obesity, where excess weight places pressure on veins and causes them to weaken

  • Pregnancy and childbirth, where physical strain places pressure on deep veins, causing them to weaken

  • Tobacco smoking, which is associated with damage to blood vessels and doubles the risk of blood clots


Can blood clots be prevented?

Some blood clots can be prevented through physical activity, a healthy lifestyle, and quality medical care. Some important tips for preventing blood clots include the following:

  • Take breaks and stretch your legs when traveling long distances

  • Perform heel-toe exercises when seated during prolonged travel and get up and walk as frequently as possible

  • Drink fluids, preferably water, especially during prolonged travel

  • Know the symptoms of blood clots and seek early medical attention if they occur

  • Know the risk factors for blood clots and make lifestyle changes, such as stopping smoking, weight control, control of cholesterol and blood pressure

  • Be aware of a family history of blood clots

In case of major surgery, injury, prolonged immobility, or when in a cast, ask your healthcare provider whether you should receive treatment to prevent blood clots and, if so, for how long. In some cases, people at high risk for blood clots or with a history of excessive clotting may be prescribed long-term anti-clotting medicines to prevent a blood clot.

If you have more questions about thrombosis symptoms, call the IHTC.

Contact Us

If you are in Indiana, call
317.871.0000 or 877.CLOTTER (877.256.8837)