D-Dimer
Understanding D-Dimer
What is D-Dimer?
A D-Dimer test detects the presence of D-dimer, a protein fragment produced when a blood clot dissolves in the body. This test helps diagnose and monitor conditions related to blood clot formation, such as deep vein thrombosis (DVT), pulmonary embolism (PE), stroke and disseminated intravascular coagulation (DIC).
During an injury, the body uses proteins to clot the blood and stop bleeding. Once the bleeding stops, the body sends other proteins to break down the clot slowly. D-dimer is a protein fragment generated during the breakdown of blood clots. A D-Dimer test determines the presence of D-dimer and helps assess the blood clot formation and breakdown in the body.
This test may be needed in individuals presenting with symptoms suggestive of blood clots, such as leg swelling, pain, redness, shortness of breath, chest pain, rapid heartbeat, or signs of abnormal bleeding. Higher than normal D-dimer levels can indicate the presence of an active blood clot, and hence, a D-Dimer test helps diagnose or rule out blood clot-related conditions such as DVT, PE, stroke, and DIC. Sometimes, this test is also used to monitor the effectiveness of treatment for these conditions. In addition, a D-dimer test also helps understand the risk and progression in cases of pneumonia and COVID-19.
No fasting is required for this test. You can eat and drink normally as per your routine. However, a duly filled coagulation requisition form is mandatory for sample collection. Before getting tested, let your doctor know if you are taking any medications, as they might interfere with the test results, and you may have to stop taking them for some time.
Test result ranges are approximate and may differ slightly between labs depending on the methodology and laboratory guidelines. Talk to your doctor about your specific test results to understand your condition, and narrate your complete medical history to your doctor to help formulate an effective treatment plan.
What is D-Dimer used for?
A D-Dimer test is done:
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To detect the presence of an inappropriate blood clot (thrombus).
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If symptoms of deep vein thrombosis (DVT), such as pain, swelling, discolored skin of the legs with surfaced and enlarged veins, etc., are observed.
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If symptoms of pulmonary embolism (PE), such as shortness of breath, coughing, back pain, pain in the chest, fast heart rate, and dizziness, are experienced.
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If symptoms of disseminated intravascular coagulation (DIC), such as nausea, vomiting, seizures, bleeding gums, and muscular and abdominal pain, are observed.
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To rule out blood clotting caused by snake bite, thrombosis with thrombocytopenia syndrome (TTS), and stroke.
What does D-Dimer measure?
A D-Dimer test measures the amount of D-dimer protein your body produces when a blood clot begins to break down. It is a byproduct of the blood clotting and clot break-down process that can be measured by analyzing a blood sample. D-dimer is typically undetectable in the blood and is produced only after a clot has formed and is broken down.
Interpreting D-Dimer results
Interpretations
A "negative" D-dimer result (D-dimer levels below a predetermined value) means that the person being tested has no acute condition or disease-causing abnormal clot formation and breakdown in the body.
A "positive" D-dimer result may indicate that there may be a significant blood clot (thrombus) formation and breakdown in the body by detecting the presence of an abnormally high level of fibrin degradation products.