Deep Venous Thrombosis (DVT) Deep-venous thrombosis, or DVT, is a blood clot that forms in the deep system of veins in your legs. It usually starts as a small clot behind one of the valves in the vein, and progresses to cause a blockage throughout the vein. Risk factors for developing DVT are prolonged sitting or lying flat, damage to lining of the vein (trauma) or abnormal blood clotting (hypercoaguable state). People at risk for DVT include people who are obese, pregnant women, women on estrogen pills, people with cancer, people with varicose veins, people confined to bed or a chair, and people who have had an injury to their legs. Patients complain of acute pain and swelling of their leg, which usually is only on one side. In severe cases, the leg can appear pale or blue.

Why is the treatment of DVT important?
A DVT can cause pain in the leg, but more importantly, the blood clot that forms in the leg can break off and become lodged in the blood vessels in the lung (pulmonary embolism), which can be life threatening. Also, if the swelling in the leg becomes severe, the blood supply to the leg can become compromised.