A D-dimer is a by-product of blood clotting and break-down, detectable through a blood test. [1][2][3] It's released when a blood clot in the body starts to dissolve.
Understanding D-dimers
D-dimers provide crucial information about the presence of blood clots in the body. They are not present in healthy individuals, or are present at very low levels. Elevated levels often indicate that the body is actively forming and breaking down clots, which can be associated with various medical conditions.
How are D-dimers formed?
- Clot Formation: When there's an injury or other trigger, the body initiates a cascade of events leading to the formation of a blood clot (thrombus).
- Stabilization: Fibrin, a protein, forms a mesh-like structure that stabilizes the clot.
- Breakdown (Fibrinolysis): As the injury heals, the body begins to break down the clot through a process called fibrinolysis.
- D-dimer Release: During fibrinolysis, plasmin (an enzyme) breaks down fibrin, releasing D-dimer fragments into the bloodstream.
What does an elevated D-dimer level mean?
An elevated D-dimer level can be associated with several conditions, including:
- Deep Vein Thrombosis (DVT): A blood clot in a deep vein, usually in the leg.
- Pulmonary Embolism (PE): A blood clot that travels to the lungs.
- Disseminated Intravascular Coagulation (DIC): A condition where blood clots form throughout the body.
- Surgery: Post-operative state increases the risk of clot formation
- Pregnancy D-dimer is generally elevated in pregnant women.
D-dimer Testing:
| Aspect | Description |
|---|---|
| Purpose | To detect the presence of blood clots and aid in diagnosing conditions like DVT and PE. |
| Sample Type | Blood sample |
| Interpretation | Elevated levels suggest clot formation and breakdown; further investigation is needed. |
| Limitations | Elevated D-dimer levels can be caused by other conditions, limiting diagnostic specificity. |
