To diagnose deep vein thrombosis (DVT), your health care provider will do a physical exam and ask questions about your symptoms. The provider will check the legs for swelling, tenderness or changes in skin color.

The tests you have depend on whether your provider thinks you are at a low or a high risk of DVT.


Tests used to diagnose or rule out DVT include:

  • D-dimer blood test. D dimer is a type of protein produced by blood clots. Almost all people with severe DVT have increased blood levels of D dimer. This test often can help rule out pulmonary embolism (PE).
  • Duplex ultrasound. This noninvasive test uses sound waves to create pictures of how blood flows through the veins. It's the standard test for diagnosing DVT. For the test, a care provider gently moves a small hand-held device (transducer) on the skin over the body area being studied. Additional ultrasounds may be done over several days to check for new blood clots or to see if an existing one is growing.
  • Venography. This test uses X-rays and dye to create a picture of the veins in the legs and feet. The dye is injected into a large vein in the foot or ankle. It helps blood vessels show up more clearly on X-rays. The test is invasive, so it's rarely done. Other tests, such as ultrasound, often are done first.
  • Magnetic resonance imaging (MRI) scan. This test may be done to diagnose DVT in veins of the belly (abdomen).


There are three main goals to DVT treatment.

  • Prevent the clot from getting bigger.
  • Prevent the clot from breaking loose and traveling to the lungs.
  • Reduce the chances of another DVT.

DVT treatment options include:

  • Blood thinners. These medicines, also called anticoagulants, help prevent blood clots from getting bigger. Blood thinners reduce the risk of developing more clots.

    Blood thinners may be taken by mouth or given by intravenous (IV) or an injection under the skin. There are many different types of blood-thinning drugs used to treat DVT. Together, you and your health care provider will discuss their benefits and risks to determine the best one for you.

    You might need to take blood thinner pills for three months or longer. It's important to take them exactly as prescribed to prevent serious side effects.

    People who take a blood thinner called warfarin (Jantoven) need regular blood tests to monitor levels of the drug in the body. Certain blood-thinning medications are not safe to take during pregnancy.

  • Clot busters (thrombolytics). These drugs are used for more-serious types of DVT or PE, or if other medications aren't working.

    Clot busters are given by or through a tube (catheter) placed directly into the clot. They can cause serious bleeding, so they're usually only used for people with severe blood clots.

  • Filters. If you can't take medicines to thin your blood, a filter may be placed into a large vein — the vena cava — in your belly (abdomen). A vena cava filter prevents clots that break loose from lodging in the lungs.
  • Support stockings (compression stockings). These special knee socks help prevent blood from pooling in the legs. They help reduce leg swelling. Wear them on your legs from your feet to about the level of your knees. For DVT, you typically wear these stockings during the day for a few years, if possible.
Compression stockings

Compression stockings

Compression stockings, also called support stockings, press on the legs, improving blood flow. A stocking butler may help with putting on the stockings.

Clinical trials

Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.

Self care

After DVT treatment, follow these tips to manage the condition and prevent complications or more blood clots:

  • Ask about your diet. Foods high in vitamin K, such as spinach, kale, other leafy greens and Brussels sprouts, can interfere with the blood thinner warfarin.
  • Take medications as directed. Your provider will tell you how long you need treatment. If you're taking certain blood thinners, you'll need regular blood tests to see how well your blood is clotting.
  • Watch for excessive bleeding. This can be a side effect of blood thinners. Ask your care provider about the warning signs. Know what to do if bleeding happens. Also ask your provider if you have activity restrictions. Minor injuries that cause bruising or even a simple cut may become serious if you're taking blood thinners.
  • Move. If you've been on bed rest because of surgery or other reasons, the sooner you get moving, the lower the chance that blood clots will develop.
  • Wear support stockings. Wear these to help prevent blood clots in the legs if your provider recommends them.

Preparing for your appointment

DVT is considered a medical emergency. It's important to get treated quickly. If there's time before your appointment, here's some information to help you get ready.

What you can do

Make a list of:

  • Your symptoms, including any that seem unrelated to deep vein thrombosis, and when they began
  • Important personal information, including notes about travel, hospital stays, any illness, surgery or trauma in the past three months, and any personal or family history of blood-clotting disorders
  • All medications, vitamins or other supplements you take, including doses
  • Questions to ask your health care provider

If possible, take a family member or friend with you to help you remember the information you're given.

For DVT, questions to ask your health care provider include:

  • What's the most likely cause of my symptoms?
  • What tests do I need?
  • What's the best treatment?
  • What are the options other than the main treatment that you're suggesting?
  • Will I need to restrict travel or activities?
  • I have other health conditions. How can I best manage these conditions together?
  • Are there brochures or other printed material I can have? What websites do you recommend?

What to expect from your doctor

Your health care provider is likely to ask you questions, such as:

  • Have you been inactive lately, such as sitting or lying down for long periods?
  • Do you always have symptoms, or do they come and go?
  • How severe are your symptoms?
  • What, if anything, makes your symptoms improve?
  • What, if anything, makes your symptoms worse?

Jun 11, 2022

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  5. What is venous thromboembolism? Centers for Disease Control and Prevention. https://www.cdc.gov/ncbddd/dvt/facts.html. Accessed April 5, 2022.
  6. Diagnosis and treatment of venous thromboembolism. Centers for Disease Control and Prevention. https://www.cdc.gov/ncbddd/dvt/diagnosis-treatment.html. Accessed April 5, 2022.
  7. Jameson JL, et al., eds. Pulmonary thromboembolism and deep-vein thrombosis. In: Harrison's Manual of Medicine. 20th ed. McGraw Hill; 2020. https://accessmedicine.mhmedical.com. Accessed April 5, 2022.
  8. Hull RD, et al. Biology of warfarin and modulators of INR control. https://www.uptodate.com/contents/search. Accessed April 5, 2022.
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