What causes a DVT?
The blood contains molecules that will naturally cause the blood to clot and become solid. This is called a thrombosis. When blood is moving through the normal veins, these molecules are unable to act and the blood stays fluid. Damage to the inside “non stick” lining of the vein causes these molecules to become activated very quickly and a thrombosis of the vein will result within a few minutes. This is a normal survival mechanism to prevent major loss of blood even from a small cut. However, if the blood is allowed to stagnate in a normal, undamaged vein for long enough, a blood clot can start to form. Blood is moved through the deep veins in the leg mainly by the action of the muscles that surround the veins. If the person is completely immobile for several hours (e.g. during an operation) then a blood clot can start to form. Small clots are quite common and normally the body dissolves the clot once the person becomes active again. However, if the clot is too extensive, then the body
