The femoral vein, a blood vessel located deep inside each of the thighs, is prone to blood clots. Known as femoral vein thrombosis, a blood clot in the femoral vein or its branches can have serious consequences.

The femoral vein transports deoxygenated blood from the lower limbs to the heart.

Without early intervention, blood clots that form in the femoral vein may travel and lodge in the heart, where they can cause conditions, such as ischemic heart disease. Ischemic means the organ — in this case, the heart — is not getting enough blood and oxygen.

Another complication is a pulmonary embolism, which can be life threatening.

This article discusses femoral vein thrombosis, its causes, prevention, and treatment options.

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Femoral vein thrombosis is a subtype of deep vein thrombosis (DVT). DVT refers, generally, to blood clots in the deep veins, usually the legs.

Individuals with femoral vein thrombosis present with some symptoms similar to those associated with DVT. Symptoms may include:

  • significant swelling of one leg
  • tenderness along the course of the femoral vein
  • increased warmth and discolored skin around the affected area

People with any of these symptoms should seek immediate medical attention. Prompt medical intervention may be necessary to reduce the risk of life threatening complications, such as a pulmonary embolism.

Femoral vein thrombosis occurs due to factors or conditions that increase the risk of blood clot formation by either slowing blood flow or damaging the endothelial lining of the blood vessel.

In some people, the specific cause of femoral vein thrombosis may be unknown.

However, experts believe the following factors can increase the risk of femoral vein thrombosis:

  • Sedentary lifestyle: Physical inactivity can slow blood flow, increasing the possibility of blood clots forming.
  • Medical conditions: Chronic diseases that damage the endothelial lining or slow blood flow can raise the chances of femoral vein thrombosis. Some examples include:
    • diabetes
    • blood clotting disorders
    • cancer
    • obesity
    • hypertension, or high blood pressure
  • Age: Although femoral vein thrombosis can occur at any age, the risk is higher in people over the age of 40.
  • Family history: People with a family history of DVT are more at risk of developing the condition as they could inherit certain genes predisposing them to abnormal blood clotting.
  • Sex: Premenopausal females are more likely to develop femoral vein thrombosis than males. After menopause, the risk is higher in males.

Delayed treatment of femoral vein thrombosis can increase the chances of developing complications. Common ones include:

Pulmonary embolism

This refers to the blockage of the pulmonary artery. Specifically, the bloodstream transports a blood clot from its original site to the lungs, and it becomes lodged in the pulmonary artery.

Pulmonary embolism is life threatening and requires emergency treatment.

Learn more about pulmonary embolism.

Venous insufficiency

Blood clots may cause valvular damage — related to valves in the leg — resulting in venous insufficiency.

Learn more about chronic venous insufficiency.

Post-thrombotic syndrome

Post-thrombotic syndrome can occur several months after a person experiences femoral vein thrombosis or DVT. It refers to a collection of symptoms, such as chronic pain, swelling, and hyperpigmented skin in the affected leg after treatment.

Learn more about post-thrombotic syndrome.

Diagnosing femoral vein thrombosis usually requires a combination of clinical assessment and diagnostic testing.

A doctor will take a medical history and conduct a physical examination to identify signs and symptoms suggestive of femoral vein thrombosis.

Thereafter, they may order the following diagnostic tests:

  • Venous ultrasonography: This noninvasive test uses high frequency ultrasound waves to create images of the veins to detect blood clots.
  • Venography: This test uses contrast-enhanced radiography to visualize the veins and reveal any blood clots. It is typically the test of choice for individuals with severe symptoms.
  • D-dimer test: This test measures the level of a chemical substance, called D-dimer, in the blood. When blood clots break, the body produces D-dimer as a byproduct. Doctors typically combine D-dimer and imaging tests to diagnose femoral vein thrombosis accurately.

Treatment can help:

  • remove any blood clot present in the femoral vein
  • prevent further blood clot formation
  • reduce the risk of complications

Doctors may recommend the following methods for femoral vein thrombosis management:


These include anticoagulants, such as intravenous heparin, which helps thin the blood and prevent new blood clot formation.

Invasive procedures

This typically involves surgical or vascular procedures, such as vena cava filter insertion or catheter-directed thrombolysis. These types of procedures help remove existing blood clots.

Some tips include:

  • avoiding a sedentary lifestyle, as physical inactivity is a major risk factor that initiates blood clot formation
  • stretching the entire body at regular intervals when on a long trip — longer than 4 hours
  • keeping adequately hydrated while traveling
  • talking to a doctor about possibly using compression socks, which can help improve blood circulation
  • always following a doctor’s recommendations and taking any anticoagulants they prescribe as directed

Early diagnosis and prompt treatment can influence the overall outlook of femoral vein thrombosis. A person’s outlook can depend on many factors, including:

  • their age
  • underlying health conditions
  • whether they experience complications

If a person becomes immobile for any reason, they need to seek medical counsel and care to prevent femoral vein thrombosis.

Below are some commonly asked questions about femoral vein thrombosis:

How serious is femoral vein thrombosis?

Left untreated, femoral vein thrombosis can be serious because the blood clot can potentially break off and travel to the lungs, causing a pulmonary embolism. This is life threatening.

The Centers for Disease Control and Prevention (CDC) estimates that 60,000–100,000 deaths in the United States each year are due to DVT and pulmonary embolisms.

Therefore, seeking early medical attention is crucial if a person has signs and symptoms that suggest femoral vein thrombosis.

Is femoral vein thrombosis a DVT?

Yes, it is. The femoral vein is the particular site affected in around 20% of people with DVT.

What is thrombophlebitis of the femoral vein?

It is a clinical condition characterized by inflammation of the femoral vein. It presents as localized pain, redness, and swelling in the thigh, and it may increase the risk of blood clots forming.

Femoral vein thrombosis refers to the presence of a blood clot in the femoral vein of the leg. Significant swelling of one leg, tenderness, and skin discoloration around the affected area characterize the condition.

Anyone with symptoms should seek immediate medical attention to prevent life threatening complications, such as a pulmonary embolism.

A sedentary lifestyle is one of the major risk factors for femoral vein thrombosis. Other factors, such as having chronic medical conditions, age, sex, and family history, can also influence the risk of developing it.

A doctor combines findings from a person’s medical history, specialized tests, and imaging to identify a blood clot in the femoral vein. Treatment usually involves medications and invasive procedures, such as surgery, to prevent blood clots and remove existing ones.