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Deep venous thrombosis

  • Alternative Names

    DVT; Blood clot in the legs; Thromboembolism; Post-phlebitic syndrome; Post-thrombotic syndrome


    Your doctor will give you medicine to thin your blood (called an anticoagulant). This will keep more clots from forming or old ones from getting bigger. These drugs cannot dissolve existing clots.

    Heparin is usually the first drug given.

    • If heparin is given through a vein (IV), you must stay in the hospital.
    • Newer forms of heparin can be given by injection once or twice a day. You may not need to stay in the hospital as long, or at all, if you are prescribed this newer form of heparin.

    A drug called warfarin (Coumadin) is usually started along with heparin.

    • Warfarin is taken by mouth. It takes several days to fully work.
    • Heparin is not stopped until the warfarin has been at the right dose for at least 2 days.
    • You will most likely take warfarin at least 3 months. Some people must take it for the rest of their lives, depending on their risk for another clot.

    When you are taking warfarin, you are more likely to bleed, even from activities you have always done.

    Changing how you take your warfarin, taking certain medicines, and eating certain foods can change the way the warfarin works in your body. If this happens, you may be more likely to form a clot or have bleeding problems. Never stop taking your medicine or change the dose without talking to your doctor.

    If you are taking warfarin:

    • Take the medicine just the way your doctor prescribed it
    • Ask the doctor what to do if you miss a dose
    • You will need to get blood tests often to make sure you are taking the right dose

    You will be given a pressure stocking to wear on your leg or legs. A pressure stocking improves blood flow in your legs, and reduce your risk for blood clots. It is important to wear these every day.

    In rare cases, surgery may be needed if medicines do not work. Surgery may involve:

    • Placement of a filter in the body's largest vein to prevent blood clots from traveling to the lungs
    • Removal of a large blood clot from the vein or injection of clot-busting medicines

    Support Groups

    Expectations (prognosis)

    Many DVTs disappear without a problem, but they can return. Some people may have long-term pain and swelling in the leg known as post-phlebitic syndrome. Wearing tight (compression) stockings during and after the DVT may help prevent this problem.

    Blood clots in the thigh are more likely to break off and cause pulmonary embolism (PE) than blood clots in the lower leg or other parts of the body.


    A blood clot can break free in the leg and travel to the lungs (pulmonary embolus) or anywhere else in the body, and can be life threatening. Rapid treatment of DVT helps prevent this problem.

    Post-phlebitic syndrome refers to long-term swelling (edema) in the leg that had the deep vein thrombosis. Changes in skin color and pain can also be present. These symptoms may be noticed right away, or may not develop for one or more years afterward. This problem is called post-thrombotic syndrome.

    Calling your health care provider

    Call your health care provider if you have symptoms of DVT.

    Go to the emergency room or call the local emergency number (such as 911) if you have DVT and you develop chest pain, difficulty breathing, coughing blood, fainting, loss of consciousness, or other severe symptoms.