D-Dimer Unit Converter

D-dimer is a small protein fragment produced when a blood clot breaks down. It is one of the final degradation products released when the body's clot-dissolving system (fibrinolysis) cuts through cross-linked fibrin.

When you are injured, your body forms a fibrin mesh to stop bleeding. Once healing begins, the enzyme plasmin breaks down that mesh and releases D-dimer into the bloodstream. A small amount of fibrin is always being formed and dissolved, so healthy people have low but detectable levels.

D-dimer is mainly used as a rule-out test. A normal result makes it very unlikely that a dangerous blood clot is present, while an elevated result signals that clotting activity has increased and further investigation may be needed.

D-dimer is produced anywhere in the body where cross-linked fibrin is broken down by plasmin. It is not made by a single organ. Instead, it is a byproduct of the normal clotting and clot-dissolving process that occurs throughout the vascular system.