Deep Vein Thrombosis



Deep vein thrombosis (DVT) is a blood clot in a vein deep in the body. A blood clot is a buildup of red blood cells, proteins, and other cells in a vein. As the clot grows, it blocks blood flow in the vein.

In DVT, blood clots happen most often in the legs and pelvis. However, they can happen elsewhere.

DVT can lead to serious and life-threatening problems such as a pulmonary embolism.

Deep Vein Thrombosis
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DVT can be caused by:

  • Injury to a vein
  • Slow blood flow and pooling of blood in a vein
  • Blood clotting problems

Risk Factors

The risk of DVT increases with age. Other things that raise the risk are:

  • Major surgery
  • Trauma or fracture
  • Personal or family history of DVT
  • Not being able to move, such as with bed rest or airplane travel
  • Changes in hormones due to pregnancy, birth control pills, and estrogen therapy
  • Medical conditions, such as:
    • Cancer
    • Obesity
    • Heart failure and heart attack
    • Certain kidney diseases
    • Inflammatory conditions such as inflammatory bowel disease and Behcet disease
    • Blood disorders
  • Having a catheter in a central vein



DVT does not always cause symptoms. When symptoms happen, they may include:

  • Pain in the affected area
  • Swelling of a leg or arm
  • Tenderness along the vein, especially near the thigh
  • Redness, paleness, or blueness of the affected leg or arm

Some may not have any symptoms until the clot moves to the lungs. This condition is called a pulmonary embolism.


The doctor will ask about symptoms and past health. A physical exam will be done.

To diagnose DVT, the doctor may test blood and blood flow with:

  • Blood tests
  • Compression ultrasound
  • Venography



The goals of treatment are to:

  • Stop the clot from growing
  • Dissolve the clot, if possible
  • Prevent other problems, such as pulmonary embolism and more clots

Treatment options are:

  • Blood thinning medicine by IV or shots—to prevent DVT. It may be used long-term.
  • Medicine delivered to the site by a catheter and x-rays—to dissolve clots. It is given for clots that are large, serious, or in an arm.
  • Compression stockings—Worn on the legs to improve blood flow.

For large and serious clots, surgery may be done, such as:

  • Thrombectomy—The clot is taken out.
  • Insertion of an inferior vena cava filter—A small device is placed in a vein. It prevents a blood clot from going to the lungs.


To help lower the risk of DVT:

  • Do not sit for long periods of time. Get up and move around.
  • If confined to bed, move arms and legs often. Change positions at least every 2 hours.
  • Carefully follow treatment for a previous DVT.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.

a (DVT; Thrombophlebitis)


American Heart Association 

American Venous Forum 


Health Canada 

Heart and Stroke Foundation of Canada 


Deep vein thrombosis (DVT). EBSCO DynaMed website. Available at: Accessed September 8, 2021.

Deep vein thrombosis. Ortho Info—American Academy of Orthopaedic Surgeons website. Available at: Accessed September 8, 2021.

Di Nisio M, van Es N, et al. Deep vein thrombosis and pulmonary embolism. Lancet. 2016;388(10063):3060-3073.

What is venous thromboembolism? Centers for Disease Control and Prevention website. Available at: Accessed September 8, 2021.