Medical Edge Newspaper Column

Triggers for Deep Vein Thrombosis (DVT)

March 13, 2009
Readers:
For most healthy adults, deep vein thrombosis (DVT), the medical term for blood clots in the legs, is extremely rare. Every year, about 350,000 Americans are affected by DVT or a pulmonary embolism, where a clot breaks away and blocks an artery to the lung — often a fatal condition.

DVT develops in the larger, "deep" veins that funneling blood back to the heart. The condition usually affects the largest veins of the legs and pelvis. Many factors increase risk of clotting, including certain cancers, advanced age, living in a nursing home, use of hormone replacement therapy, pregnancy, recent childbirth, a family history of DVT and obesity.

Any of several situations can trigger DVT. Airplane rides lasting six hours or more and long periods of sitting for any reason pose risks. That's why travelers are urged to stretch or walk every hour and stay well hydrated. Hospitalization for a sudden medical problem also creates risks. Trauma or a fracture in the leg area or pelvis puts patients at high risk, as does major surgery — especially surgery that involves hip and knee replacement or is in the pelvic area.

Many DVTs develop and grow quite large before symptoms appear. Eventually, in most cases, symptoms are present and can include:

• Swelling in the ankle of the affected leg. Typically only one leg is affected.
• Leg pain that often starts in the calf and can feel like a cramp.
• Redness or warmth over the affected area and fever.

These symptoms should prompt a visit with a physician. Ultrasound and other imaging techniques are used to diagnose DVT. Treatment seeks to prevent the clot from becoming bigger and to reduce the risk of pulmonary embolism. Most people with DVT are prescribed anticoagulant medications to take for three months or longer.

— Adapted from Mayo Clinic Health Letter