Deep Vein Thrombosis

Deep vein thrombosis affects close to 1 million Americans a year. It is usually in the legs after long periods of sitting or immobility. Staying in shape and not smoking can reduce the risk.

Deep Vein Thrombosis Overview

Reviewed: July 22, 2014

Deep vein thrombosis, or DVT, is a blood clot that forms in a vein deep in the body, such as the lower leg, thigh, or pelvic region. Blood clots occur when blood abnormally thickens and clumps together, blocking off normal blood flow back to the heart.

Symptoms of DVT include warmth and tenderness over affected area, pain or swelling in the part of the body affected, and redness of the skin over the affected area. Only about half of the people who have DVT have signs and symptoms.

DVT can be caused by physical, chemical, or biological factors. Such factors may include surgery, serious injuries, inflammation, and immune responses. Inherited conditions such as factor V Leiden may cause blood to be more likely to clot.Obesity and smoking are risk factors that increase the likelihood of DVT as well.

The goals of treating DVT are to prevent the blood clot from getting bigger or breaking off and moving to the lungs, as well as reduce chances of having another blood clot. Anticoagulants are used to prevent the clots from becoming bigger (enoxaparin, dalteparin, fondaparinux, warfarin). Thrombolytics are used to quickly dissolve large blood clots that cause severe symptoms. Because thrombolytics can cause sudden bleeding, they're used only in life-threatening situations. Graduated compression stockings can reduce leg swelling caused by a blood clot. 

Deep Vein Thrombosis Symptoms

The signs and symptoms of deep vein thrombosis (DVT) might be related to DVT itself or pulmonary embolism (PE). See your doctor right away if you have signs or symptoms of either condition. DVT can cause serious, possibly life-threatening problems if it goes untreated.

Only about half of the people who have DVT have signs and symptoms. These signs and symptoms occur in the leg affected by the deep vein clot. They include:

  • Swelling of the leg or along a vein in the leg
  • Pain or tenderness in the leg (you may feel only when standing or walking)
  • Skin that feels warm to the touch
  • Changes in skin color (redness)

Deep Vein Thrombosis Causes

Blood clots can form in your body's deep veins if you:

  • Have damaged your vein which can be caused by physical, chemical, or biological factors. Such factors may include surgery, serious injuries, inflammation, and immune responses.
  • Are on bed rest or not being able to move for long periods of time. This may occur after surgery or if you are traveling for a long time.
  • Have an inherited conditions such as factor V Leiden. In this case, your blood is thicker or more likely to clot than normal.
  • Take hormone therapy or birth control pills.
  • Have had recent surgery (most commonly hip, knee, or female pelvic surgery).

The risk factors for deep vein thrombosis (DVT) include:

  • A history of DVT
  • Injury to a deep vein from surgery, a broken bone, or other trauma
  • Pregnancy and the first 6 weeks after giving birth
  • Recent or ongoing treatment for cancer
  • A central venous catheter. This is a tube placed in a vein to allow easy access to the bloodstream for medical treatment
  • Advancing age, especially older than 60 years old
  • Being overweight or obese
  • Smoking
  • Having certain diseases or conditions such as a history of heart attack, stroke, congestive heart failure, lupus
  • Family history of blood clots
  • Fractures in the pelvis or legs

Most cases of DVT affect the legs, but DVT can happen in the upper body as well. Some factors that may increase risk for developing a DVT in the upper body includes:

  • Having a long, thin flexible tube called a catheter inserted in your arm vein
  • Having a pacemaker or implantable cardioverter defibrillator (ICD)
  • Having cancer
  • Performing vigorous repetitive activities with your arms

Your risk for DVT increases if you have more than one of the risk factors listed above.

Deep Vein Thrombosis Diagnosis

Your doctor will diagnose deep vein thrombosis (DVT) based on your medical history, a physical exam, and test results. He or she will identify your risk factors and rule out other causes of your symptoms.

For some people, DVT might not be diagnosed until after they receive emergency treatment for pulmonary embolism (PE).

Medical History

To learn about your medical history, your doctor may ask about your overall health, ask about the medications you take, ask about recent surgeries, and if you have been recently treated for cancer.

Physical Exam

During your physical exam, your doctor will check your legs for signs of DVT, such as swelling or redness. He or she also will check your blood pressure and listen to your heart and lungs.

Diagnostic Tests

Your doctor may order an ultrasound, a D-dimer test, or a computed tomography venography to look for blood clots.

Other Tests

Your doctor may order other tests to diagnose DVT such as magnetic resonance imaging. Your doctor may also order blood tests to determine whether you have an inherited blood clotting disorder that can cause DVT.

Living With Deep Vein Thrombosis

If you've had a deep vein blood clot, you're at greater risk for another one. During treatment and after, take steps to prevent deep vein thrombosis (DVT).

  • Take all medicines that your doctor prescribes to prevent or treat blood clots
  • Follow up with your doctor for tests and treatment
  • Use compression stockings as your doctor directs to prevent leg swelling
  • If you are going to sit for long periods of time, try to exercise your lower leg muscles.
  • Try to get out of bed and move around as soon as soon as you can after surgery or after being sick.
  • Avoid smoking

Contact your doctor at once if you have any signs or symptoms of DVT. These symptoms include swollen areas, pain or tenderness, increased warmth in swollen or painful areas, or red or discolored skin on the legs.

Travel Tips

Although the risk of developing DVT while traveling is low, the risk increases if the travel time is longer than 4 hours or you have other DVT risk factors.

During long trips, try to:

  • Walk up and down the aisles of the bus, train, or airplane. If traveling by car, stop about every hour and walk around.
  • Move your legs and flex and stretch your feet. In addition, exercise your lower leg muscles during long trips.
  • Wear loose and comfortable clothing.
  • Drink plenty of fluids and avoid alcohol.

If you have risk factors for DVT, your doctor may suggest you wear compression stockings while traveling.

Ongoing Health Care Needs

DVT often is treated with blood-thinning medicines. These medicines can cause bleeding which can be life threatening. Call your doctor right away if you notice any signs or symptoms of bleeding.

You might want to wear a medical ID bracelet or necklace that states you're at risk of bleeding. If you're injured, the ID will alert medical personnel of your condition.

Take all medicines as prescribed, and have blood tests done as your doctor advises. Discuss the following with your doctor:

  • Tell your doctor about all the medications you take including over-the-counter medicines and herbals. Some medications and/herbals can interact with your medications and increase your risk for bleeding.
  • If you are taking warfarin (Coumadin), ask your doctor about your diet. Foods that contain vitamin K, found in green leafy vegetables, can affect how well warfarin (Coumadin) works.
  • Ask your doctor about alcohol use.

Deep Vein Thrombosis Treatments

Doctors treat deep vein thrombosis (DVT) with anticoagulants, thrombolytics, devices and therapies. The main goals of treating DVT are to:

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



Anticoagulants are the most common medicines for treating DVT and work by decreasing the ability for your blood to clot and prevent the clots from becoming bigger.

Warfarin and heparin are two blood thinners used to treat DVT. Warfarin Coumadin) is given in pill form. Heparin is given as an injection or through an IV tube. Your doctor will discuss the options with you.

  • Your doctor may treat you with both heparin and warfarin at the same time since heparin acts quickly and it takes 2 to 3 days before Warfarin starts to work. Once the warfarin starts to work, the heparin may be stopped.

These medications can cause bleeding which is life threatening.

Blood thinners can cause bleeding. As a result, your doctor will order routine blood tests such as PT and PTT tests. These tests measure the blood's ability to clot as well as determine if the dose you are taking is appropriate. If you notice any signs or symptoms of bleeding, call your doctor right away.

Treatment for DVT using blood thinners usually lasts for 6 months. In some cases, treatment may last longer.


Doctors prescribe these medicines to quickly dissolve large blood clots that cause severe symptoms. Because thrombolytics can cause sudden bleeding, they're used only in life-threatening situations.

Thrombin Inhibitors

For those who can not take heparin, your doctor may prescribe a Thrombin inhibitors, which is a newer type of medicine.

Other Types of Treatment

Vena Cava Filter

In some cases, a vena cava filter can be used. Vena cava filter prevents blood clots from moving to your lungs. The filter is inserted inside a large vein called the inferior vena cava. The filter catches clots before they travel to the lungs. Although this type of treatment can prevent PE, it won't prevent the formation of other blood clots.

Graduated Compression Stockings

Graduated compression stockings can reduce leg swelling caused by a blood clot. These stockings are worn on the legs from the arch of the foot to just above or below the knee.

Graduated compression stockings can help decrease swelling that may be associated with a blood clot in the leg. Graduated compression stockings prevents the blood from pooling and clotting.

  • There are three types of compression stockings:
    • Support pantyhose
    • Over-the-counter compression hose. These stockings give a little more pressure than support pantyhose
    • Prescription-strength compression hose offer the greatest amount of pressure

Talk with your doctor about how long you should wear compression stockings.

Deep Vein Thrombosis Prognosis

Many DVTs disappear without a problem, but there is a chance they can return.

Some people may have long-term pain and swelling in the leg called post-phlebitic syndrome.

Some people may also have pain and changes in skin color. These symptoms can appear right away or may not develop for 1 or more years afterward. To help prevent this problem, you can wear tight (compression) stockings during and after the DVT.

Blood clots in the thigh are more likely to break off and travel to the lungs (pulmonary embolus, or PE) compared to blood clots in the lower leg or other parts of the body.