Deep vein thrombosis is a condition where a clot is formed in the deep veins of usually the leg. Such a clot could obstruct blood flow in the leg. A part of the clot may break off and obstruct the flow of blood to the lungs. Here is an animation to help you understand how a clot is formed in the deep veins and the complications of deep vein thrombosis.
Disclaimer :
The procedure/surgery depicted in this video is for information purpose only. Depending on the patient condition, the procedure/surgery methodology could vary in actuality.