The signs and symptoms of deep vein thrombosis (DVT) may be related to DVT itself or to pulmonary embolism (PE). See your doctor right away if you have signs or symptoms of either condition. Both DVT and PE can cause serious, possibly life-threatening complications if not treated.
Deep Vein Thrombosis: Only about half of the people who have DVT have signs or 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, which you may feel only when standing or walking
- Increased warmth in the area of the leg that’s swollen or in pain
- Red or discolored skin on the leg
Your doctor will diagnose deep vein thrombosis (DVT) based on your medical history, a physical exam, and the results from tests. He or she will identify your risk factors and rule out other causes of your symptoms.
Medical History. To learn about your medical history, your doctor may ask about:
- Your overall health
- Any prescription medicines you’re taking
- Any recent surgeries or injuries you’ve had
- Whether you’ve been treated for cancer
Physical Exam. During the physical exam, your doctor will check your legs for signs of DVT. He or she also will check your blood pressure and your heart and lungs.
Diagnostic Tests. Your doctor may recommend tests to find out whether you have DVT. The most common tests used to diagnose DVT are:
- Ultrasound. This is the most common test for diagnosing deep vein blood clots. Ultrasound uses sound waves to create pictures of blood flowing through the arteries and veins in the affected leg.
- A D-dimer test. This test measures a substance in the blood that’s released when a blood clot dissolves. If the test shows high levels of the substance, you may have a deep vein blood clot. If your test is normal and you have few risk factors, DVT isn’t likely.
- Venography. This test is used if ultrasound doesn’t provide a clear diagnosis. Dye is injected into a vein, and then an x ray is taken of the leg. The dye makes the vein visible on the x ray. The x ray will show whether blood flow is slow in the vein. This may indicate a blood clot.
- Other less common tests used to diagnose DVT include magnetic resonance imaging (MRI) and computed tomography (CT) scanning. These tests provide pictures of your organs and tissues and are commonly used to diagnose pulmonary embolisms (PE).
Deep vein thrombosis (DVT) is treated with medicines and certain devices and therapies. The main goals of treating DVT include:
- Stopping the blood clot from getting bigger
- Preventing the blood clot from breaking off and moving to your lungs
- Reducing your chance of having another blood clot
Anticoagulants are the most common medicines for treating DVT. They’re also known as blood thinners. These medicines decrease your blood’s ability to clot. They also stop existing blood clots from getting bigger. However, blood thinners can’t break up blood clots that have already formed. (The body dissolves most blood clots with time.)
Blood thinners can be taken as either a pill, an injection under the skin, or through a needle or tube inserted into a vein (called intravenous, or IV, injection).
Warfarin and heparin are two blood thinners used to treat DVT. Warfarin is given in pill form. (Coumadin is a common brand name for warfarin.) Heparin is given as an injection or through an IV tube. There are different types of heparin. Your doctor will discuss the options with you.
Your doctor may treat you with both heparin and warfarin at the same time. Heparin acts quickly. Warfarin takes 2 to 3 days before it starts to work. Once the warfarin starts to work, the heparin is stopped.
Newer anticoagulants are under development that will be easier to use than warfarin, because there is less bleeding risk without the monitoring required for warfarin.
Latest NIH Research
- The National Heart, Lung, and Blood Institute (NHLBI) is conducting or sponsoring several studies looking at the relationship between a patient’s genetic makeup and how the patient’s body uses the anticoagulation drug warfarin. Better anticoagulation control could lead to a decrease in the rate of dangerous blood clots and bleeds among patients. Warfarin is a drug used to reduce the risk, but it must be dosed properly to avoid dangerous complications. NHLBI is also sponsoring studies looking at better ways to detect and treat DVT and PE. For more information about ongoing trials go to: www.clinicaltrials.gov
- NHLBI has been conducting studies on heart vein valve damage associated with DVT and how to preserve and/or replace the damaged valve function.
- Researchers are investigating whether there are genetic and other predispositions for DVT that occur without any known origin.