Most people are unaware of deep venous thrombosis (DVT) and its possible consequences. DVT is a blood clot in a deep vein, usually in the legs. It is one of the leading causes of death in the United States. These blood clots can be dangerous if they break off and travel to the lungs. When this happens, it causes a serious, potentially life-threatening condition called pulmonary embolism.
The precise number of people affected by pulmonary embolism caused by DVT is unknown, but estimates range from 300,000 to 600,000 (1 to 2 per 1,000, and in those over 80 years of age, as high as 1 in 100) each year in the United States, according to the Centers for Disease Control and Prevention.
DVT can occur at any age. The good news is that DVT is preventable and treatable if discovered early.
Here, Antonios P. Gasparis, MD, professor of surgery and director of the Stony Brook Center for Vein Care, answers frequently asked questions about DVT and what you need to know about it.
Q: What causes DVT?
A: Blood clots may form in veins due to immobility, for example after surgery or if you sit for a long flight or car trip. Other risk factors for developing deep vein thrombosis include:
- Injuries from an accident
- Prior history of DVT
- Family history of DVT
- Having a central venous catheter
- Cancer
- Being overweight
- Taking birth control pills or hormone therapy
- Pregnancy
- Smoking
Q: What are the symptoms of DVT?
A: Common symptoms are:
- Swelling of the leg
- Pain or tenderness in the leg
- Increased warmth in the area of the leg that is swollen or painful
- Red or discolored skin in the area of the leg that is swollen or painful
Prolonged immobility increases the risk of DVT because blood in the deep veins
becomes sluggish, pools, and is more prone to form a clot.
Q: What are the symptoms of pulmonary embolism?
A: Some people may not find out that they have DVT until a clot breaks off and travels to the lung resulting in a pulmonary embolism. The symptoms of pulmonary embolism include:
- Chest pain when taking in a deep breath
- Shortness of breath
- A sensation of your heart beating fast
- Fever
- Cough
Q: How is DVT prevented?
A: Proactive protection, also called prophylaxis, for DVT is far easier than treating it after it has occurred. Patients are evaluated for risk of DVT and are treated with appropriate prophylaxis while in the hospital. Prophylaxis may include:
- Frequent ambulation and simple leg exercises to help keep blood moving.
- Medications such as blood thinners. Some patients may be at high risk for using blood thinners. If so, compression stockings and / or a compression sleeve / pump will be placed on the patient’s legs or feet to help squeeze blood out and prevent clots from forming.
- Mechanical devices such as a compression pump. It is important for the patient to keep the compression sleeve / pump on at all times, except when walking.
Q: How is DVT diagnosed?
A: Your physician will obtain your medical history and will perform an examination to determine if deep vein thrombosis is present. To verify the diagnosis, your physician may also order a duplex ultrasound, which is a noninvasive test that evaluates the deep veins for the presence of clots.
Q: How is DVT treated?
A: Treatment of DVT includes blood thinners, such as heparin or warfarin (Coumadin), to prevent the blood clot from progressing and dislodging to the lungs. If ordered by your physician, these medications are taken for at least three to six months. Frequent blood tests are required so that your physician can evaluate how well the blood thinners are working, and to determine if the dose of your medicine needs to be adjusted.
In addition, special stocking called "compression stockings" may be used to help prevent further clotting and reduce the pain and swelling that can happen with deep vein thrombosis.
In rare cases, a physician may recommend placement of a vena cava filter to prevent embolisms from traveling to the lungs. This device is generally used for patients who cannot take blood thinners, are at high risk for embolism, or have recurrence of deep vein thrombosis. Certain patients may have the option of filter removal once risk of pulmonary embolism no longer exists.
For some patients, removal of the blood clot may be offered. This is done by a minimally invasive procedure using special catheters with medication to break down and remove the clot. Removal of blood clots is usually performed on younger, active patients to prevent long-term complications such as chronic leg pain, swelling, and leg ulcers.
Understanding your own risk is important: use this online risk calculator to find out. Read Dr. Gasparis' blog about air travel and DVT risk. For more information, please visit our DVT team at 631-444-4DVT (444-4388).