Frecuently asked questions
Deep vein thrombosis (DVT) and pulmonary embolism (PE) are two types of blood clots that make up venous thromboembolisms (VTE). A deep vein thrombosis is the formation of a blood clot in a deep vein, most commonly in the legs but they can also occur elsewhere in the body. A pulmonary embolism occurs when a part of this clot breaks free and moves through the blood vessels to the lungs.
Clotting is a normal process that helps to stop bleeding, for example, when you get a cut in the skin. Blood clots can form in the veins if:
• The blood flow is slowed down. This can occur when people are immobile for a long period of time (long distance travel, being bed-bound)
• The lining of the vein is damaged. This can occur after surgery or trauma.
• There is a problem in the blood that makes it clot more easily. Pregnancy, some medications and genetic disorders can make the blood “stickier.”
Each year, 1 to 2 in every 1000 people develops a VTE. They are more common in the elderly population and the risk increases to 1 in 100 in people over the age of 80.
VTE can occur in anyone, but some factors can increase the risk. Having more than one risk factor further increases the risk. Some risk factors are listed below:
- Age: A VTE can occur at any age, but the risk increases dramatically after the age of 50
- Existing medical problems: cancer, recent surgery, trauma
- Previous history of a DVT or PE
- Long periods of immobility: bedrest , long car rides or flights
- Hormonal changes: pregnancy, women who are taking the birth control pill or women who are on hormone replacement therapy
- Inherited risk: people who have an inherited problem with clotting (thrombophilia)
The severity of symptoms depends on the location and the size of the blood clot. Symptoms can greatly vary between individuals. Signs and symptoms of a DVT (clot in the leg) and PE (clot that has traveled up into the lungs) are different.
When planning a long trip, the following preventive steps are recommended, especially if you have other risk factors for VTE:
- Drink plenty of fluids, minimize alcohol and caffeine consumption
- Walk and stretch at regular intervals
- Wear loose-fitting clothing
- Special stockings that compress the legs below the knee may help prevent blood clots from forming should be used in people with additional risk factors for VTE. However, talk to your GP before you try these stockings because some people should not wear them.
The following tests may be performed to diagnose a VTE:
- Blood tests: There are no diagnostic blood tests for VTE, but blood test may be useful in order to exclude a VTE diagnosis, and may also provide useful information when a VTE has been diagnosed.
- Ultrasound: This test is more often used to look for a DVT in the legs. A small handheld device is placed over the veins to check the blood flow in them.
- CT scan (CTPA): This imaging test can be done to see if there are any clots in the lung (PE).
Other tests that might be done:
- Ventilation/perfusion (V/Q) scan: This imaging test measures how well air and blood move through the lungs. It is used to diagnose PE.
- Venography: For this test, dye is injected put into a vein and an X-ray picture is taken. The dye can show whether there is a clot in the vein.
Blood clots are most often treated with medications. Virtually everyone who gets a VTE will need to be treated with anticoagulants (blood thinners) for a period. In some cases, lifelong use of these medications may be necessary. For more extensive blood clots in the leg, it may be necessary to use thrombolytic (clot dissolving) drugs directly into the vein using a catheter. For large blood clots in the lungs that effect the heart and blood pressure, clot dissolving therapy may also be given directly in the blood. In rare cases, massive and life-threatening pulmonary embolisms (blood clots in the lungs) may require surgery.
Last updated: 20.11.2014 08:22