Deep Vein Thrombosis (DVT)

What is Deep Vein Thrombosis (DVT)

Deep vein thrombosis is a condition in which a blood clot forms in a deep vein, such as a lower leg, thigh, or arm vein. A clot is blood that has thickened into a gel or solid.

This condition is dangerous. It can lead to serious and even life-threatening complications if the clot travels to the lungs and causes a blockage (pulmonary embolism). It can also damage veins in the leg. This can result in leg pain, swelling, discoloration, and sores (post-thrombotic syndrome).

What are the causes?

This condition may be caused by:

  • A slowdown of blood flow.
  • Damage to a vein.
  • A condition that causes blood to clot more easily, such as an inherited clotting disorder.

What increases the risk?

The following factors may make you more likely to develop this condition:

  • Being overweight.
  • Being older, especially over age 60.
  • Sitting or lying down for more than four hours.
  • Being in the hospital.
  • Lack of physical activity (sedentary lifestyle).
  • Pregnancy, being in childbirth, or having recently given birth.
  • Taking medicines that contain estrogen, such as medicines to prevent pregnancy.
  • Smoking.
  • A history of any of the following:
    • Blood clots or a blood clotting disease.
    • Peripheral vascular disease.
    • Inflammatory bowel disease.
    • Cancer.
    • Heart disease.
    • Genetic conditions that affect how your blood clots, such as Factor V Leiden mutation.
    • Neurological diseases that affect your legs (leg paresis).
    • A recent injury, such as a car accident.
    • Major or lengthy surgery.
    • A central line placed inside a large vein.

What are the signs or symptoms?

Symptoms of this condition include:

  • Swelling, pain, or tenderness in an arm or leg.
  • Warmth, redness, or discoloration in an arm or leg.

If the clot is in your leg, symptoms may be more noticeable or worse when you stand or walk. Some people may not develop any symptoms.

How is this diagnosed?

This condition is diagnosed with:

  • A medical history and physical exam.
  • Tests, such as:
    • Blood tests. These are done to check how well your blood clots.
    • Ultrasound. This is done to check for clots.
    • Venogram. For this test, contrast dye is injected into a vein and X-rays are taken to check for any clots.

How is this treated?

Treatment for this condition depends on:

  • The cause of your DVT.
  • Your risk for bleeding or developing more clots.
  • Any other medical conditions that you have.

Treatment may include:

  • Taking a blood thinner (anticoagulant). This type of medicine prevents clots from forming. It may be taken by mouth, injected under the skin, or injected through an IV (catheter).
  • Injecting clot-dissolving medicines into the affected vein (catheter-directed thrombolysis).
  • Having surgery. Surgery may be done to:
    • Remove the clot.
    • Place a filter in a large vein to catch blood clots before they reach the lungs.

Some treatments may be continued for up to six months.

Follow these instructions at home:

If you are taking blood thinners:

  • Take the medicine exactly as told by your health care provider. Some blood thinners need to be taken at the same time every day. Do notskip a dose.
  • Talk with your health care provider before you take any medicines that contain aspirin or NSAIDs. These medicines increase your risk for dangerous bleeding.
  • Ask your health care provider about foods and drugs that could change the way the medicine works (may interact). Avoid those things if your health care provider tells you to do so.
  • Blood thinners can cause easy bruising and may make it difficult to stop bleeding. Because of this:
    • Be very careful when using knives, scissors, or other sharp objects.
    • Use an electric razor instead of a blade.
    • Avoid activities that could cause injury or bruising, and follow instructions about how to prevent falls.
  • Wear a medical alert bracelet or carry a card that lists what medicines you take.

General instructions

  • Take over-the-counter and prescription medicines only as told by your health care provider.
  • Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
  • Wear compression stockings if recommended by your health care provider.
  • Keep all follow-up visits as told by your health care provider. This is important.

How is this prevented?

To lower your risk of developing this condition again:

  • For 30 or more minutes every day, do an activity that:
    • Involves moving your arms and legs.
    • Increases your heart rate.
  • When traveling for longer than four hours:
    • Exercise your arms and legs every hour.
    • Drink plenty of water.
    • Avoid drinking alcohol.
  • Avoid sitting or lying for a long time without moving your legs.
  • If you have surgery or you are hospitalized, ask about ways to prevent blood clots. These may include taking frequent walks or using anticoagulants.
  • Stay at a healthy weight.
  • If you are a woman who is older than age 35, avoid unnecessary use of medicines that contain estrogen, such as some birth control pills.
  • Do notuse any products that contain nicotine or tobacco, such as cigarettes and e-cigarettes. This is especially important if you take estrogen medicines. If you need help quitting, ask your health care provider.

Contact a health care provider if:

  • You miss a dose of your blood thinner.
  • Your menstrual period is heavier than usual.
  • You have unusual bruising.

Get help right away if:

  • You have:
    • New or increased pain, swelling, or redness in an arm or leg.
    • Numbness or tingling in an arm or leg.
    • Shortness of breath.
    • Chest pain.
    • A rapid or irregular heartbeat.
    • A severe headache or confusion.
    • A cut that will not stop bleeding.
  • There is blood in your vomit, stool, or urine.
  • You have a serious fall or accident, or you hit your head.
  • You feel light-headed or dizzy.
  • You cough up blood.

These symptoms may represent a serious problem that is an emergency. Do not wait to see if the symptoms will go away. Get medical help right away. Call your local emergency services (911 in the U.S.). Do not drive yourself to the hospital.


  • Deep vein thrombosis (DVT) is a condition in which a blood clot forms in a deep vein, such as a lower leg, thigh, or arm vein.
  • Symptoms can include swelling, warmth, pain, and redness in your leg or arm.
  • This condition may be treated with a blood thinner (anticoagulant medicine), medicine that is injected to dissolve blood clots,compression stockings, or surgery.
  • If you are prescribed blood thinners, take them exactly as told.
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