Deep Vein Thrombosis

This article originally appeared in the Dr. William C. Herrick Community Health Care Library January-March 2015 newsletter.

Deep Vein Thrombosis (DVT) is sometimes called the silent killer. An estimated 350,000 to 600,000 people per year have an episode of DVT or the resulting pulmonary embolism (PE), which causes an estimated 100,000 deaths, making it as common and as fatal as a heart attack. The causes of DVT vary widely and include: long distance travel (more than 4 hours) by air, bus, or car, obesity, smoking, sitting too long, age, cancer and cancer treatments, pregnancy, use of birth control pills or hormone replacement therapy, surgery, and the greatest single risk factor – hospitalization. A family history of blood clots will also increase a person’s risk factors. DVT tends to recur in people who have had it before. Recent studies also show a correlation between the use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, naproxen (Aleve) and ibuprofen (Advil, Motrin), and an 80% increased risk for DVT. Patients who have had DVT should consult their doctors before using NSAIDs. So far, studies have not been able to pinpoint which NSAIDs might pose the greatest risk or which patients might be most vulnerable.

DVT occurs when a blood clot forms, usually in deep veins in the calf of the leg, although they can also form in arm veins. Warning signs for DVT are pain or swelling, usually in one leg or arm, and warmth or redness in the affected area. When DVT progresses to a pulmonary embolism, symptoms can also include shortness of breath, chest pain, elevated heart rate, rapid pulse, feeling lightheaded or dizzy, coughing up blood, and sudden collapse with no obvious reason. This happens when the clot breaks off in the leg vein and travels, usually to the lungs, as the lungs are a natural filter for clots. See a doctor immediately if you think you might have a PE, as the death rate rises rapidly if not treated in a timely manner.

Diagnosis of DVT clots are by Venous Doppler Ultrasound (non-invasive sound waves) in a test given by a radiologist. Other diagnostic methods include a blood test for a clot-dissolving substance in blood called D-dimer. For a pulmonary embolism, a CT scan of the lungs or ventilation perfusion lung scan (shows how much air and blood are getting into the alveoli of the lungs) is performed. Treatment can include compression stockings and blood anti-coagulants and can take weeks to 2-3 months to dissolve the clot(s). The medications currently available for treating DVT must be monitored closely by a doctor. New medications are becoming available which will require less medical supervision.

Steps to reduce the risk of DVT include maintaining a healthy weight, exercising regularly, not smoking, and moving around following long-term bed rest. If sitting for long periods of time, it is recommended that you stand for 5 minutes every hour, exercise your legs while sitting, take a walk every 2-3 hours, and wear loose-fitting clothes while travelling and sitting in a confined space.

The Herrick Library has a new DVD called Preventing Deep Vein Thrombosis and Pulmonary Embolism: Dangerous Blood Clots, a short, 24-minute film which explains DVT very well. A new book available for checkout called Get Up!: Why Your Chair Is Killing You and What You Can Do About It explores the negative consequences of sitting to our health, both mental and physical. If you sit at work or home or you travel and sit for long periods, you should know about DVT and how to avoid it.

Websites for more information:

The Dr. William C. Herrick Community Health Care Library is supported by the Grossmont Healthcare District to meet the health information needs of local residents. It is a comprehensive consumer health library that is free, open to the public, and accessible via the Internet.