Deep vein thrombosis (DVT) occurs when a blood clot (thrombus) forms in one or more of the deep veins in your body, usually in your legs. Deep vein thrombosis can cause leg pain or swelling, but also can occur with no symptoms. Deep vein thrombosis can develop if you have certain medical conditions that affect how your blood clots. It can also happen if you don't move for a long time, such as after surgery or an accident, or when you're confined to bed.
Deep vein thrombosis signs and symptoms can include: • Swelling in the affected leg. Rarely, there's swelling in both legs. • Pain in your leg. The pain often starts in your calf and can feel like cramping or soreness. • Red or discolored skin on the leg. • A feeling of warmth in the affected leg. Deep vein thrombosis can occur without noticeable symptoms.
The blood clots of deep vein thrombosis can be caused by anything that prevents your blood from circulating or clotting normally, such as injury to a vein, surgery, certain medications and limited movement.