What is DVT?

What Is Deep Vein Thrombosis? What causes DVT? Who is at risk for DVT? What are the signs and symptoms of DVT?

Is DVT serious? How is DVT diagnosed? Can DVT be prevented? What is the treatment for DVT?

What is Deep Vein Thrombosis?

Deep vein thrombosis or DVT is a serious condition caused by blood clots developing in the deep veins, most often occurring in the legs.¹ The formation of a blood clot is called thrombosis.¹ DVT can cause swelling, tenderness, redness, warmth, and possibly life-threatening complications if not treated.¹

What causes DVT?

Blood clots can form in the body’s deep veins when¹:

• Damage occurs to a vein’s inner lining.¹ This damage may result from injuries caused by physical, chemical, and biological factors.¹
• Blood flow is sluggish or slow.¹ Lack of motion can cause sluggish or slowed blood flow.¹ This may occur after surgery, being confined to bed for a long time due to an illness, or traveling for a long time.¹
• When a person’s blood is thicker or more likely to clot than usual.¹ Certain inherited conditions (such as factor V Leiden) increase blood’s tendency to clot.¹ This also is true of treatment with hormone replacement therapy or birth control pills.¹

Who is at risk for DVT?

Many factors increase the risk for developing DVT, including¹:

• A history of DVT.¹
• Disorders or factors that make your blood thicker or more likely to clot than normal. Certain inherited blood disorders (such as factor V Leiden) will do this.¹ This also is true of treatment with hormone replacement therapy or using birth control pills.¹
• Injury to a deep vein from surgery, a broken bone, or other trauma.¹
• Slow blood flow in a deep vein from lack of movement.¹ This may occur after surgery, being confined to bed for a long time due to illness, or traveling for a long time.¹
• Pregnancy and the first 6 weeks after giving birth.¹
• Recent or ongoing treatment for cancer.¹
• A central venous catheter.¹ This is a tube placed in vein to allow easy access to the bloodstream for medical treatment.¹
• Being older than 60 (although DVT can occur in any age group).¹
• Being overweight or obese.¹

There is an increased risk for developing DVT in people who have more than one of the risk factors listed above.¹

What are the signs and symptoms of DVT?

Only about half of people with DVT have symptoms.¹ These symptoms occur in the leg that is affected by the deep vein clot and include¹:

• Swelling of the leg or along a vein in the leg¹
• Pain or tenderness in the leg, which may be felt only when standing or walking¹
• Increased warmth in the area of the leg that's swollen or in pain¹
• Red or discolored skin on the leg¹

Is DVT serious?

Yes, DVT is a serious condition because a blood clot in a deep vein can break off and travel through the bloodstream.¹ The loose clot is called an embolus.¹ When the clot travels to the lungs and blocks blood flow, the condition is called pulmonary embolism or PE.¹

PE is a very serious condition.¹ It can damage the lungs and other organs in the body and cause death.¹

How is DVT diagnosed?

DVT is diagnosed based on medical history, a physical exam, and test results.¹ Doctors need to identify risk factors and rule out other causes for the symptoms.¹ In addition, various tests may be conducted including¹:

• Physical exams¹
• Ultrasonography¹
• D-dimer testing¹
• Venography¹
• Magnetic resonance imaging (MRI)¹
• Computed tomography (CT)¹
• Ventilation perfusion scan¹

Can DVT be prevented?

Steps can be taken to prevent DVT.¹ People at risk for DVT or PE may be able to prevent the condition by¹:

• Seeing a doctor for regular checkups.¹
• Taking all medicines as prescribed by a doctor.¹
• Getting out of bed and moving around as soon as possible after surgery or illness.¹ This lowers the risk of developing a blood clot.¹
• Exercising lower leg muscles during long trips.¹ This helps prevent a blood clot from forming.¹

People who have had DVT or PE before, can help prevent future blood clots by following the above steps and¹:

• Taking all prescribed medicines to prevent or treat blood clots¹
• Following up with a doctor for tests and treatment¹
• Using compression stockings to prevent leg swelling as recommended by a doctor¹

Contact your doctor at once if you have any signs or symptoms of DVT or PE.¹

What is the treatment for DVT?

The main goals of treating DVT are to¹:

• Stop the blood clot from getting bigger¹
• Prevent the blood clot from breaking off and moving to the lungs¹
• Reduce the chance of having another blood clot¹

Medicines are used to prevent and treat DVT including¹:

• Anticoagulants, also known as blood thinner.¹ These medicines decrease your blood’s ability to clot.¹ They also stop existing blood clots from getting bigger.¹ Warfarin and heparin are two blood thinners used to treat DVT.¹ Warfarin is given in pill form.¹ (COUMADIN^® is a common brand name for warfarin.¹) Heparin is given as an injection or through an IV tube.¹ Sometimes, doctors treat patients with both heparin and warfarin at the same time.¹ Heparin acts quickly.¹ Warfarin takes 2 to 3 days before it starts to work.¹ Once the warfarin starts to work, the heparin is stopped.¹
• Thrombin inhibitors interfere with the blood clotting process.¹ They’re used to treat blood clots in patients who can’t take heparin.¹
• Thrombolytics are given to quickly dissolve a blood clot.¹ They’re used to treat large blood clots that cause severe symptoms.¹ Because thrombolytics can cause sudden bleeding, they’re used only in life-threatening situations.¹

REFERENCE

1. National Heart Lung Blood Institute Website. Diseases and conditions index: deep vein thrombosis. http://www.nhlbi.nih.gov/health/dci/Diseases/Dvt/DVT_All.html. Accessed October 3, 2008.