If they find D-Dimer in your blood, I believe it indicates your blood has the right condition for making clots. That way your doctors can use that information to determine what exactly is wrong with your blood that is causing you to form blood clots. So once they correct the problem, a D-Dimer test can tell if more clots are forming somewhere in your body. If it is, like me, my doctors ordered a special technology to find where in the body the clot or clots are forming, so they can be dissolved. First they do the whole upper body, then the next scan does the legs. Since your own body defense can dissolve a clot over time, I believe D-Dimer is what is released into the blood as the clot breaks down. Glad I could give you my knowledge. Becky