Deep vein thrombosis (DVT)

DVT usually occurs in a deep leg vein, a large vein that runs through the muscles of the calf and the thigh. It can also develop in your arms, chest or other areas of your body.

It develops when blood pools in the veins and a clot forms. This may happen because there is compression of the vessel so the vein is narrower, or if the normal “muscle pump” of the leg is not pumping blood back to the heart.

Deep vein thrombosis and pulmonary embolism (PE) are linked as DVT can cause pain and swelling in the leg which may lead to complications such as PE. PE is when a piece of blood clot breaks off into the bloodstream and blocks one of the blood vessels in the lungs.

DVT is not common, but it can be dangerous. A clot can cause organ damage or even death.

Deep vein thrombosis causes include:

  • Being immobile for long periods, for example, a long-haul flight
  • Deep vein thrombosis after surgery can occur
  • Blood vessel damage
  • Medical or genetic factors that cause your blood to clot more easily than normal
  • Pregnancy
  • Women taking the contraceptive pill and hormone replacement therapy (HRT)

Risk factors include:

  • Obesity
  • Smoking
  • Dehydration
  • Age (most common in people over 60)

What are its symptoms?

Deep vein thrombosis can be difficult to identify. It can also develop without any noticeable symptoms. Signs include:

  • Swelling in the affected leg
  • Pain in your leg that feels like cramping

If you develop signs or symptoms of deep vein thrombosis, contact your doctor for guidance.

Warning signs of a pulmonary embolism include:

  • Sudden shortness of breath
  • Chest pain or discomfort when you cough or breathe deeply
  • Feeling lightheaded or dizzy
  • Coughing up blood

If you experience any of these, get to a hospital immediately.

How is it diagnosed?

Diagnosing a deep vein thrombosis can be difficult as the symptoms are similar to many other health problems. Your doctor will ask you about your medical history and perform a physical examination and prescribe certain tests.

Deep vein thrombosis diagnostic tests include:

  • Duplex Doppler: A combination of ultrasound (which uses high-frequency sound waves to create an image of the leg veins) and a flow “probe”, which shows the direction of the flow of the blood in the veins. This combination will show any blockage in the veins.
  • Contrast venography: This involves injecting a substance into the veins that shows up on X-ray.
  • Magnetic resonance imaging (MRI): This creates detailed images of the inside of your body.

An option may also be a thrombosis blood test. A sample may be sent to the laboratory to test for conditions that cause increased blood-clotting tendency.

What are your treatment options?

Deep vein thrombosis treatment options include medication, several devices and therapies. The main goals of treating DVT are to:

  • Stop the clot from getting bigger
  • Stop the clot from breaking off and moving to your lungs
  • Reduce your chance of another clot.

Medicines include:

  • Anticoagulants or blood thinners such as warfarin and heparin
  • Thrombin Inhibitors, which interfere with the blood-clotting process
  • Thrombolytics, which quickly dissolve large blood clots causing severe symptoms. These are only used in life-threatening situations.

Other treatments include:

  • A vena cava filter (for patients with recurrent DVT and high risk of PE): Catches blood clots before they travel to the lungs.
  • Compression stockings: Can reduce leg swelling caused by a blood clot.

Can it be prevented?

There are several things you can do to help prevent DVT occurring. These include deep vein thrombosis home treatments such as:

  • Stopping smoking
  • Controlling your weight
  • Exercising regularly
  • Eating a healthy, balanced diet
  • Anticoagulants (medicines that reduce the ability of the blood to clot) for prolonged bed rest

If you’re going into hospital for surgery, speak to your doctor about your risk of developing a blood clot while you are there, and what precautions you can take.

Deep vein thrombosis from sitting can occur, so if you’re going travelling and plan to be inactive for lengthy periods, make sure you stay hydrated, avoid alcohol, take short walks and wear elastic compression stockings.

The accuracy of this information was checked and approved by physician Dr Thomas Blake in June 2015