D-dimer
The D-dimer test is a laboratory blood test that detects the presence of D-dimer — a protein fragment formed during the breakdown of blood clots (thrombi) in the body. D-dimer is a marker of activation of the blood coagulation system and fibrinolysis (the process of clot dissolution).
Blood coagulation is an important physiological process that prevents excessive blood loss when blood vessels are damaged. After a thrombus forms, the body initiates mechanisms to dissolve it, resulting in fragments including D-dimer. An elevated D-dimer level indicates increased activity of thrombus formation and fibrinolysis.
Indications for the test:
- Suspected deep vein thrombosis (DVT) — blood clots in deep veins, most often in the legs.
- Suspected pulmonary embolism (PE) — blockage of the pulmonary artery by a clot.
- Disseminated intravascular coagulation (DIC) — pathological formation of multiple clots throughout the body.
- Complicated pregnancy (gestosis, preeclampsia, diabetes).
- Monitoring the effectiveness of thrombolytic and anticoagulant therapy.
- Suspected stroke or acute cerebral ischemia.
Clinical significance:
A normal D-dimer level allows for a high probability exclusion of thrombosis. Elevated D-dimer is not specific for thrombosis, as it can also be observed in inflammation, infections, cancer, trauma, surgery, pregnancy, old age, and other conditions accompanied by activation of blood coagulation.
Test method: immunoturbidimetric blood analysis.
Sample material: venous blood.
The physician evaluates the test results in conjunction with the patient’s clinical data and, if necessary, orders additional tests to clarify the diagnosis.
Thus, the D-dimer test is an important diagnostic tool for detecting and excluding thrombotic conditions, as well as for monitoring treatment in patients at risk of thrombosis.