What is Deep Vein Thrombosis (DVT)?

When a blood clot (thrombus, or thrombosis) develops in one of the deep veins of the body it is called a deep venous thrombosis (DVT). The most common location for a deep venous thrombosis to occur is in the legs. DVT is a serious medical condition. The clinical importance can range from insignificant to life threatening.

DVTs need to be diagnosed and treated quickly to help avoid serious clinical sequella (effects). In some cases of DVT, the blood clot may break loose from the vein, travel through the heart and lodge in the lungs. This is called a pulmonary embolus (PE). Some pulmonary emboli are minor, and some are fatal.

DVT and PE as a group are called venous thromboembolism disease (VTE). VTE is the fourth leading cause of death in the Western world. It is estimated that 600,000 cases of VTE occur every year in the U.S.

Deep vein thrombosis

What is thrombosis?

Thrombosis, or thrombus, is the medical term for blood clot. For the most part, blood clots are a good thing for our body. They stop bleeding (hemorrhage). When we are bleeding, such as after trauma or during surgery, blood clots help stop the bleeding. However, sometimes a blood clot forms where we do not want it to, such as in a vein that is not bleeding. An abnormal blood clot that forms in the deep veins is called a deep vein thrombosis, or DVT. An abnormal blood clot that forms in a superficial vein is called a superficial vein thrombosis, or phlebitis.

Blood Clot Disease Symbol

What is a deep vein?

Our limbs have two venous systems, the deep venous system and the superficial venous system. The deep vein system carries the majority of the blood flow out of the legs and back to the heart. The deep vein system in the leg is comprised of:

  • Common femoral vein
  • Femoral vein
  • Deep femoral vein
  • Popliteal vein
  • Tibial veins
  • Gastocneimius veins
  • Soliel veins

What are risk factors for developing a Deep Vein Thrombosis (DVT)?

There are a variety of factors that increase your likelihood of developing a DVT. The more risk factors you have, the more likely you are to have a DVT in your lifetime. Risk factors for developing a DVT are:

  • Active cancer
  • Previous DVT
  • Being hospitalized
  • Recent surgery
  • Being immobile or sitting for a long period of time, such as an overseas airline flight
  • Cigarette smoking
  • Older age (over 60 years old)
  • A hypercoaguable disorder of the blood (also called thrombophilia)
  • Birth control pills, rings, or implants
  • Family history of DVT

DVT are you at risk

What are the symptoms of a Deep Vein Thrombosis (DVT)?

Classic symptoms of a DVT in the leg include:

  • Pain in the leg, especially the calf
  • Swelling in the leg
  • Discolored skin on the leg
  • Warm, tender, red skin on the leg

Sometimes DVTs do not cause symptoms.

pain in feet and legs

How is Deep Vein Thrombosis (DVT) diagnosed?

The definitive diagnosis of DVT is made with a venous duplex ultrasound examination of the limb. Of course, a history and physical examination, as well as a review of the risk factors can be important as well. Occasionally, blood tests may be ordered that are markers for blood clot formation, but these tests are non-specific. The gold standard in most situations is a venous duplex ultrasound. An ultrasound examination is painless, not harmful (no x-rays), and is done as an outpatient.


What are the treatment options for Deep Vein Thrombosis (DVT)?

The main stay of treatment of deep vein thrombosis is anticoagulation (blood thinner medication). New, fast acting medicines (Xarelto, Eliquis, and others) have made a paradigm shift in the treatment of DVT. Rarely is hospitalization necessary for the treatment of DVT or PE. The new medications are much easier to manage that the older medications (Coumadin, Warfarin), which are rarely used today to treat DVT and PE.

Blood thinners (anticoagulation medicine) does not dissolve the clot. Rather, it prevents new fresh clot from forming on the existing DVT. The body has a natural enzyme in the blood called plasminogen that functions to break up clot. Clot that is not dissolved turns to scar tissue in the vein over time.

The length of time a patient is on blood thinners can vary depending on the situation. Times can range from 3 months to a year. In some cases of recurrent DVT or PE, lifetime anticoagulation is recommended.

Occasionally, other treatment modalities are indicated in certain situations. For patients with extensive thrombosis of the larger iliac and femoral veins causing obstruction of blood flow out of the leg, sometimes a procedure is done to try to open up the vein by a combination of removing or breaking up the clot and inserting a stent in the vein to keep it open. This procedure used in less than 1% of DVTs.

In some cases, when anticoagulation is not possible, such as active bleeding, recent or pending major surgery, a procedure is performed where a filter is placed in the inferior vena cava to stop a potential pulmonary embolus from reaching the lungs. This is called an IVC filter. It is only done in specific situations and is not part of the routine treatment of DVT or PE.

The goals of DVT treatment are to:

  • Prevent the blood clot from increasing in size and breaking free to form a pulmonary embolism.
  • Prevent deep vein thrombosis from occurring again.
  • Help control side effects, such as swelling