Deep vein thrombosis (DVT) occurs when a blood clot forms in a vein, usually in the leg. Since blood in veins is returning to the lungs for oxygenation, the clot can be pushed into the lungs and cause a pulmonary embolism, which can result in partial or full restriction of blood supply to the lungs. Depending on the severity of the embolism, either stress on the heart and lungs or fatality can result.
Deep veins are attached to muscles, leading to the inferior and superior vena cavae. These two central veins represent the main collection source for all blood returning to the lungs. Since the vena cavae are rather large, it is easy for a clot from a smaller vein to quickly pass through them to create a pulmonary embolism. As such, deep vein thrombosis is a medically urgent condition.
Unfortunately, deep vein thrombosis can be completely asymptomatic in about half of the cases. If symptomatic, those afflicted may notice a feeling of warmth and a change in skin color. The leg may appear blue or red. Additionally, swelling and leg pain may be present. Pain may worsen when walking or standing.
Certain factors may increase the risk of developing deep vein thrombosis. Episodes of DVT most frequently occur in people who have had recent hip or cardiac surgery. High levels of platelets, which significantly increase blood clotting, can also create susceptibility, as can cancer.
Those on long flights are at a rare but increased risk. Deep vein thrombosis is also a risk for people over 60, pregnant women and those who have just given birth, and those who are obese. Having more than one risk factor increases the likelihood of experiencing DVT.
If deep vein thrombosis is suspected, a physician may run several tests to confirm diagnosis. Ultrasounds can sometimes spot a clot. A venography is another common diagnostic procedure. The physician injects dye into the veins and takes X-rays to see if the flow of dye has been stopped, indicating the presence of a clot.
Once diagnosed, there are several treatments for deep vein thrombosis. A physician may prescribe anticoagulants, either injected like heparin, or taken orally like warfarin, to reduce further clotting. Additional treatments can include placing a stent-like filter in the vena cavae to prevent clots from passing into the lungs. In very rare cases, surgery may need to be performed to remove excessively large pulmonary embolisms from the lungs, but generally pulmonary embolism can be resolved by the above treatments.
Recommendations for preventing deep vein thrombosis include wearing graduated compression stockings, which apply pressure to the legs. Elevating the legs and walking or standing every 30 minutes may additionally help reduce clotting. Those who have just had surgery are advised to attempt mobility as soon as possible for this reason. If one is taking a long flight, physicians recommend getting up and walking for a few minutes every couple of hours.
In some cases of deep vein thrombosis (DVT) there may be no symptoms, but possible symptoms can include:
pain, swelling and tenderness in one of your legs (usually your calf)
a heavy ache in the affected area
warm skin in the area of the clot
redness of your skin, particularly at the back of your leg, below the knee
DVT usually (although not always) affects one leg. The pain may be made worse by bending your foot upward towards your knee.
If DVT is not treated, a pulmonary embolism (a blood clot that has come away from its original site and become lodged in one of your lungs) may occur. If you have a pulmonary embolism, you may experience more serious symptoms such as:
breathlessness, which may come on gradually or suddenly
chest pain, which may become worse when you breathe in
sudden collapse
Both DVT and pulmonary embolism are serious conditions that require urgent investigation and treatment.
Treatment for deep vein thrombosis (DVT) -- a blood clot deep in a vein -- ranges from medication to self-care to surgery. Discuss treatment options with your doctor.
There is more than one goal of treatment for deep vein thrombosis (DVT). The goals include:
Preventing a clot from growing
Preventing a clot from breaking off and traveling to the lung or other organ
Avoiding long-lasting complications, such as leg pain and swelling
Preventing blood clots from recurring
Blood thinners (also called anticoagulants) are the most common type of treatment for DVT. The two main types of anticoagulants are heparin and warfarin (Coumadin).
Blood thinners can:
Keep a clot from growing or breaking off
Prevent new clots from forming
But blood thinners cannot:
Thin blood, despite their name
Dissolve an existing clot
Heparin: Traditionally, people have received heparin intravenously in the hospital for about five to seven days. However, low-molecular-weight heparin is a new DVT treatment. It's effective within hours, reducing complications and hospitalizations. You can do the injections at home, once or twice daily, on an outpatient basis. And because it is more consistent and predictable, it doesn't require regular blood tests.
Warfarin: As a DVT treatment, you take warfarin (Coumadin) by pill once a day, beginning while you're still on heparin. Treatment may continue for three to six months. While on warfarin, you will need regular blood tests to ensure you have the correct dosage -- too little increases your clot risk, too much increases your risk for bleeding. Warfarin can also interact with other medicines, vitamins, or certain foods rich in vitamin K -- making regular monitoring even more important.
If you have DVT, your body will dissolve a blood clot over time, but damage can occur inside your vein in the meantime. For this reason, your doctor may recommend a clot-busting drug called a thrombolytic agent.
This DVT treatment may be necessary:
For larger clots
If you're at high risk for pulmonary embolism
If you have DVT in an arm, instead of a leg
Catheter-directed thrombolysis rapidly breaks up a clot, restoring blood flow. It may also preserve valve function in the vein that contained the clot. The procedure is done in the hospital and carries a higher risk of bleeding problems and stroke than does anticoagulant therapy.
This is how a catheter-directed thrombolysis is done to treat DVT: with imaging guidance, an interventional radiologist inserts a thin tube (catheter) into and through a vein in your leg. The radiologist then puts the tip of the catheter into the clot and infuses a clot-busting drug directly into it. If the vein appears narrowed, the radiologist may do a balloon angioplasty or stent placement to widen it and help prevent future blockages.
If blood thinners or thrombolysis procedures are not possible, or don't work well, your doctor may recommend an alternative treatment for DVT. These include:
This is a small metal device that is temporarily inserted to capture blood clots and prevent them from moving to other areas of your body. The filter allows blood to pass through the vein as it normally would.
An interventional radiologist or vascular surgeon inserts the filter into the vena cava, which is the main vein going back to the heart from your lower body. To reach this vein, which is in your abdomen, the doctor inserts the filter into a leg, neck, or arm vein. Ask your doctor how long the filter needs to stay in place.
Elevating the affected leg and using a compression device may help reduce symptoms of DVT, such as swelling and pain. Your doctor may also prescribe graduated compression stockings to reduce the risk of recurrence. You wear this DVT treatment from the arch of your foot to just above or below your knee.
In very rare cases, surgery is required to remove a deep vein clot. This may be true if you have a severe type of DVT that does not respond well to nonsurgical DVT treatment. This is called phlegmasia cerulea dolens.