What is deep vein thrombosis (dvt)?

A deep vein thrombosis (DVT) is a blood clot in certain veins, usually in the legs, pelvis, or arms. Blood clots in these veins need to be treated because they can get bigger, break loose, and travel through the bloodstream to the lungs. A blood clot in a lung can be life-threatening.

The doctor may have given you a blood thinner (anticoagulant). A blood thinner can stop the blood clot from growing larger and prevent new clots from forming. You will need to take a blood thinner for at least 3 months.

The doctor has checked you carefully, but problems can develop later. If you notice any problems or new symptoms, get medical treatment right away.

DVT often doesn't cause symptoms. Or it may cause only minor ones. When symptoms happen, they include:

• Swelling in the affected area of the leg or arm.
• Redness and warmth in the affected area.
• Pain or tenderness. You may have pain only when you touch the affected area or when you stand or walk.

Sometimes a pulmonary embolism is the first sign that you have DVT.

If your doctor thinks you may have DVT, you will probably have an ultrasound test. You may have other tests as well.

Treatment for DVT usually involves taking blood thinners. They prevent blood clots by increasing the time it takes a blood clot to form. They also help prevent existing blood clots from getting larger.

Your doctor also may suggest that you prop up or elevate your leg or arm when possible, take several walks a day, and wear compression stockings. These measures may help reduce the pain and swelling that can happen with DVT.

To help prevent DVT, you might take an anticoagulant medicine. After an illness or surgery, you can try to get up and out of bed often. You might wear compression stockings. You may try leg exercises that can help blood flow.

If your doctor thinks that you have DVT, you probably will have an ultrasound test to measure the blood flow through your veins and help find any clots that might be blocking the flow.

To see if you need an ultrasound, the doctor will do a physical exam. This will include checking your heart and lungs and checking your legs for warmth, swelling, bulging veins, or changes in skin color. Your doctor will also ask questions about your past and current health. These questions may include:

• Do you have any swelling or pain in your legs?
• Have you had a blood clot before?
• What medicines do you take?
• Have you had surgery recently, or have you been on any long trips lately?

Other tests

More tests may be used when ultrasound results are unclear. These tests may help diagnose or exclude a blood clot. These tests may include:

• D-dimer test.
• MRI.
• CT scan.

If your doctor thinks you might have a pulmonary embolism, your doctor may test your lungs.

Anticoagulant medicines, also called blood thinners, are used to prevent and treat DVT.

These medicines prevent new clots from forming. They also prevent existing clots from getting larger. They don't get rid of existing clots.

Different types of anticoagulants are used. Talk with your doctor about which medicine is right for you.

If you are in the hospital, you might be given an anticoagulant as a pill, a shot, or in a vein through an I.V. After you go home, you might give yourself shots for a few days. For long-term treatment, you'll likely take a pill.

You might take anticoagulants for at least 3 months. You may take them for a much longer time, maybe even the rest of your life. The length of time will be based on your health and your risk for a pulmonary embolism.

Many things increase your risk for DVT. These include:

• Being older than 40.
• Being overweight.
• Not taking anticoagulant medicine as prescribed.
• Having to stay in bed for more than 3 days (such as in a hospital).
• Sitting for a long time, especially when traveling long distances.
• Being pregnant, using hormonal birth control, or using hormone therapy.
• Having a recent surgery or injury that involved the legs, hips, belly, or brain.
• Having certain health problems, such as cancer, blood vessel disease, or an inherited clotting disorder.
• Smoking.

A blood clot in a deep vein (DVT) may break loose. It if does, it can travel to the lungs and block blood flow (pulmonary embolism). This is an emergency.

The risk of a pulmonary embolism can depend on the location of the blood clot. A pulmonary embolism is more likely if a blood clot is at or above the knee than if it is in the calf. But a blood clot in a calf also has a chance of causing a pulmonary embolism.

After the first time you have DVT, there is a risk of having blood clots again. Your risk can depend on what caused the clot and how it was treated. Your doctor will treat you to try to prevent clots from happening again.

If you have had DVT, you have a risk of a painful complication called post-thrombotic syndrome. Anticoagulant medicine may help lower the risk of this complication.

Causes of a blood clot in a deep vein (DVT) include:

• Slowed blood flow. This can happen when you're not active for long periods of time. For example, clots can form if you are paralyzed, are confined to bed, or must sit while on a long flight or car trip.
• Abnormal clotting problems that make the blood clot too easily or too quickly. This may be caused by certain health problems, such as cancer or a genetic clotting disorder. Pregnancy, hormonal birth control, and hormone therapy can also make blood more likely to clot.
• Surgery or an injury to the blood vessels. Blood is more likely to clot in veins shortly after they are injured.

Deep vein thrombosis (DVT) is a blood clot (thrombus) in a deep vein, usually in the legs. These clots require medical care right away.

These clots are dangerous because they can break loose, travel through the bloodstream to the lungs, and block blood flow in the lungs (pulmonary embolism). Pulmonary embolism is often life-threatening. DVT can also lead to long-lasting problems. It may damage the vein and cause the area near the clot to ache, swell, and change color.

Blood clots most often form in the calf and thigh veins, and less often in the arm veins or pelvic veins. Diagnosis and treatment of DVT in other parts of the body are similar.