Deep-Vein Thrombosis Frequently Asked Questions (FAQ)
Many people have suffered from deep-vein thrombosis, or DVT, without even knowing
its name. So it’s not surprising that patients and healthcare professionals alike
want to know more about this condition. Below are some answers designed to broaden
or refresh your knowledge about DVT.
Q. What is Deep-Vein Thrombosis (DVT)?
A. Deep-vein thrombosis (DVT) is a common but serious medical condition
that occurs in approximately two million Americans each year.1 DVT occurs when a blood clot (thrombus) forms in
one of the large veins, usually in the lower limbs, leading to either partially
or completely blocked circulation. The condition may result in health complications,
such as a pulmonary embolism (PE) and even death if not diagnosed and treated effectively.
Q. What is a Pulmonary Embolism (PE)?
A. A pulmonary embolism (PE) occurs when a blood clot is lodged
in the artery that carries blood from the heart to the lungs (pulmonary artery),
causing a severe dysfunction in respiratory function. PEs often come from the deep
leg veins and travel to the lungs through blood circulation. Symptoms include sudden
shortness of breath (that becomes worse with breathing), and rapid heart and respiratory
rates.
Q. Why do blood clots form?
A. Blood clots form to help heal the body after an injury. For
example, clots are what stop the bleeding in a cut or wound. In most situations,
blood clots are a natural part of the healing process. They enable the injured tissue
to begin to repair itself without excessive blood loss. In the case of DVT, however,
the body signals the clotting process to occur unnecessarily at the wrong time and
in the wrong place.12
Q. Does DVT always occur in the legs?
A. Blood clots can occur anywhere in the body. However, DVT occurs
only in deep veins. Most often it occurs in the legs, thighs, and pelvis.
Q. How do I know if my patient is at risk for DVT?
A. Although some people may be at risk for developing DVT, DVT
can occur in almost anyone. Some risk factors or triggering events to discuss with
your patient include, but are not limited to:13
- Congestive heart failure or respiratory failure
- Restricted mobility
- Cancer
- Obesity
- Age over 40 years
- Recent surgery
- Smoking
- Prior or family history of venous thromboembolism (VTE)
*This is a partial list of risk factors
Q. What age group is at risk for DVT?
A. DVT occurs most commonly in adults over 40, but anyone
at risk can develop it.
Q. What are the symptoms of DVT?
A. Symptoms of DVT may include pain, swelling, tenderness, discoloration
or redness of the affected area, and skin that is warm to the touch. However, as
many as half of all DVT episodes produce minimal symptoms or are completely "silent."
Because a number of other conditions — including muscle strains, skin infections,
and phlebitis (inflammation of veins) — display symptoms similar to those of DVT,
the condition may be difficult to diagnose without specific tests.14 Advise your patients
to see you immediately if they have any of the symptoms listed above.
Q. How many people in the United States are affected
by DVT?
A. DVT occurs in about 2 million Americans each year, and up to
600,000 people are hospitalized in the United States each year for DVT and its primary
complication, PE.1
An estimated 300,000 first-time cases of DVT occur in the United States every year.9 More people
die in the United States from PE than from breast cancer and AIDS combined.1
Q. Is long-distance travel safe if I am at risk for
DVT?
A. If you are at risk for DVT, or have experienced a prior DVT
or PE, you can still make long-distance trips, as long as you take some simple precautions.
Recommend that before patients leave for a long trip, they practice calf and leg
exercises they can do while sitting, and that during their trip; they stretch their
legs as much as possible. They may also want to wear compression stockings to help
the circulation of blood in the legs. Remind them to stay hydrated; dehydration
can increase the concentration of clotting factors in the blood. If patients will
be traveling for more than four hours, you may consider recommending treatment with
an anticoagulant, or "blood thinner," before they leave.15
Q. How is DVT diagnosed?
A. In the diagnosis of DVT, you will take into account the patient’s
specific risk factors, the patient’s symptoms, and the results of objective tests,
such as some method of imaging the clot. Possible tests include: duplex ultrasound,
venography and magnetic resonance imaging (MRI), and the d-Dimer test. Please see
the examination section of the toolkit to get more detailed information on the tests
used to diagnose DVT.16
Q. How is DVT/PE treated?
A. The initial treatment of both DVT and PE is anticoagulants,
also known as "blood thinners." These medications do not actually thin blood; instead,
they block the action of various clotting factors and prevent blood clots from growing
in order to allow the body’s own nature processes to destroy clots over time.
Q. After being diagnosed with DVT or PE, what limitations
will my patient experience?
A. DVT and PE usually resolve successfully, allowing patients to
return to their previous activities. Advise your patient to listen to his or her
body while exercising, but recognize that immobility is an important risk factor
for DVT and PE, so activity is important in helping to prevent future blood clots.
Q. What is the chance that my patient will have another
DVT or PE?
A. A patient’s chance of having another DVT or PE depends on the
specifics surrounding his or her first DVT or PE. If the blood clot occurred as
a result of surgery or trauma, and the risk factor was considered temporary, then
the risk of having another DVT or PE may be very low. If the blood clot occurred
spontaneously, without any risk factors being present, the risk of another clot
is 30 percent over the next 10 years.17 Obviously, a patient’s risk of having another
DVT or PE will be higher if he or she is in a high-risk category (e.g., has cancer).
Q. I'm in good physical condition, so do I need to worry
about deep vein thrombosis?
A. Most healthy people may be at low risk of developing DVT, but
it can happen. Be aware of the
risk factors and that over time your risk factors can change. Assess your risk on a regular basis, and if you observe
anything suspicious, speak with your healthcare provider right away.
Q. I'm taking oral contraceptives. Does that mean my
risk is higher?
A. Yes. Both oral contraceptives and hormone replacement therapy may increase the tendency of
the blood to clot. Keep in mind, however, that millions of women have taken oral
contraceptives without encountering this problem; the affected population is relatively
small.
Q. Does being overweight affect my risk of developing
deep vein thrombosis?
A. Obesity is a
risk factor for both cardiovascular disease and DVT. It makes it more difficult
for blood to circulate throughout the body and often results in low activity levels,
both of which can increase your risk of DVT.
Q. If I develop DVT, how long will it take to medically
treat?
A. In patients with an easily identified and reversible cause of
a deep vein thrombosis, 4 to 6 weeks of therapy may be sufficient.
For cases in which the risk of developing new thromboses remains high (such as in
patients with certain cancers or genetic abnormalities), therapy may need to be
continued for months to years. Some patients remain on oral medication for life.
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