Dangers of deep-vein thrombosis

Mar 20, 2010 at 1:47 p.m. ET

Each year 400,000 Americans develop deep-vein thrombosis (DVT), with approximately half of those cases resulting in a blood clot called a pulmonary embolism (PE), a potentially fatal condition. What’s most shocking is DVT can happen to anyone, regardless of age or fitness level. To learn more about the condition and how to prevent it, SheKnows chatted with Dr. John Kaufman, chief of vascular and interventional radiology at Oregon Health & Science University Hospital and author of Vascular and Interventional Radiology: The Requisites.

Deep Vein Thrombosis

Q&A with Dr. John Kaufman on DVT

Causes of DVT

SheKnows.com: What is DVT and what causes it?

Dr. Kaufman: DVT refers to the sudden clotting-off of the main veins that drain the legs, arms, abdomen and chest of blood. This blocks the return of blood to the heart, causing swelling and pain. Clots can also break free and go to the lung, causing a PE, which can be lethal.

Clotting of the blood can be caused by:

  • stagnant blood, which may occur from long periods of immobility.
  • damage to veins, like that from major trauma such as a broken pelvis.
  • a condition that increases the tendency of blood to clot, such as an inherited blood disorder or a cancer.

Risk factors for DVT

SheKnows.com: Is there any group who's particularly susceptible to developing DVT?

Dr. Kaufman: DVT is more common as we age and in patients with inherited blood clotting disorders, such as Protein C Deficiency, cancer and women who are on birth control pills, people who have suffered a major trauma and anybody who is immobile for long periods of time. If you have had a DVT in the past, you are more likely to have another DVT than the average person. DVT is also slightly more common after very long (more than eight-hour) plane rides.

Symptoms of DVT

SheKnows.com: What are the signs and symptoms of DVT?

Dr. Kaufman: Unfortunately, almost half of DVT cases are silent, especially if they are small or develop in small veins. The most common signs are achy pain in the affected limb, swelling, pain when using the affected limb, and tenderness when squeezing it. If these symptoms are combined with shortness of breath, pain in the chest or pain when taking a deep breath, this may indicate a PE has occurred. In women, repeated unexplained spontaneous miscarriages can also be a sign of a clotting disorder that requires evaluation by a hematologist.

Dangers of DVT

SheKnows.com: Why is DVT so dangerous?

Dr. Kaufman: The immediate threat for most patients is the risk of PE. In a very small number of patients the DVT can be so severe that the arterial blood flow into the limb (usually the leg) is compromised, resulting in amputation. The long-term threat is more common – bad varicose veins, constant swelling in the limb, pain and a breakdown of the skin leading to ulceration. This is termed "post-thrombotic syndrome" and can be very debilitating.

Diagnosing DVT

SheKnows.com: How is DVT diagnosed?

Dr. Kaufman: The best method is by ultrasound – it is quick, non-invasive and does not require radiation. If your doctor suspects that you have had a PE, you will probably need a CT scan of the chest.

SheKnows.com: Say a woman is diagnosed with DVT, what should she do next?

Dr. Kaufman: You will need to be under the care of a physician and will likely be prescribed some form of blood thinner, which are usually prescribed for three to six months and may require monitoring of blood levels with frequent blood tests. You may also need to spend a few nights in the hospital.

Treatments for DVT

SheKnows.com: What kinds of DVT treatments exist?

Dr. Kaufman: Blood thinners are a part of all DVT treatments, but a new approach is to use catheters and X-ray guidance to dissolve or breakup the clots when they involve the veins of the thigh and/or pelvis. This is the subject of a big multi-center trial right now and may prevent post-thrombotic syndrome. If, for some reason, you cannot be treated with blood thinners or clot-busting drugs, then a metal device called a vena cava filter can be placed in the main vein that drains the blood from the legs to the heart to trap any clots that might break free and cause a PE.

Tips to prevent DVT

SheKnows.com: What can women do to prevent DVT?

Dr. Kaufman: Most important, if you think you may have any risk factor (such as a family history of blood clots), contact your physician for an evaluation. Staying well hydrated, moving your legs frequently during long plane or car rides, and exercise are good measures as well. Also, knee-high or thigh-high over-the-counter graded compression stockings that help squeeze the leg veins can prevent DVT. Additionally, women on birth control pills should not smoke.

Be proactive if you think you may have DVT

SheKnows.com: Any final thoughts on DVT?

Dr. Kaufman: DVT is more common than we realize and causes more problems than we may think, but there are many good treatments available. The diagnosis is easy. If you think you might have a blood clot, don't hesitate to seek evaluation. If you are diagnosed with one, try to understand why it occurred and follow up with any testing for a clotting disorder that your doctor orders.

More ways to prevent blood clots