What is Deep Vein Thrombosis?

Deep Vein Thrombosis is a blood clot (thrombosis) that forms in the deep vein system of the lower leg--usually between the ankle and the upper calf. The condition is serious, potentially fatal, and very difficult to diagnose by external examination. Symptoms, if they occur, might include muscle tension in the lower leg, a dull ache or sudden painful tear, or a cramp in the calf with swelling and elevated body temperature.

Symptoms rarely occur, though, since the clot formation may develop very rapidly, detach from the wall of the vein and move through the blood stream before anyone recognizes what's happening. The clot may travel through the veins and lodge in the heart or more likely in the lungs, resulting in sudden death. If the clot remains lodged in the legs, very serious damage may occur to the vein, or even to the leg's entire venous system. Clots can cause tissue damage, skin lesions, ulceration, and possibly removal of the limb.