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D-dimer immunoassay (quantitative) with probe-based detection

Published: August 9, 2026Updated: August 16, 2026

This test measures a protein fragment called D-dimer, which forms when blood clots break down. It helps assess the risk of blood clots or conditions like deep vein thrombosis (DVT) or pulmonary embolism.

Quick summary

["D-dimer helps identify potential blood clot risks but isn’t a standalone diagnosis—results guide further testing."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
49445-0
Short code
T gondii DNA # BAL NAA+probe
Synonyms
T gondii DNA # BAL NAA+probe
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
probe-amp-tar
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Matters

D-dimer is a marker for fibrin degradation, appearing when clots dissolve. Elevated levels suggest recent clot activity, but they can also rise with inflammation or other conditions. Your doctor may order this test to evaluate symptoms like leg swelling, chest pain, or unexplained fatigue that could point to clots.

How the Test Works

A small blood sample is taken and analyzed using an immunoassay method that detects D-dimer fragments. The probe-based detection identifies these fragments with high sensitivity, helping quantify their presence in your blood.

Sample & Preparation

This test uses whole blood drawn from a vein. No special preparation is needed, but fasting isn’t required. If you’re on blood thinners, let your provider know—this may affect results.

What to Expect

Results typically arrive within 24–48 hours. A high D-dimer level may prompt additional imaging (like a CT scan) or further blood tests to confirm or rule out clots. Low levels usually mean no active clotting is detected.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

D-dimer

Frequently asked questions

What does a high D-dimer mean?
A high D-dimer level strongly suggests recent clot formation, especially if combined with symptoms like leg pain, swelling, or shortness of breath. However, it’s not definitive—your doctor will consider other factors, like medical history and imaging results, to diagnose conditions like DVT or pulmonary embolism.
What does a low D-dimer mean?
A low D-dimer level typically means there’s little to no evidence of recent clot activity. This can help rule out blood clots in certain situations, but it doesn’t guarantee you’re completely free of risk. Your doctor may still recommend other tests or monitoring.
Can D-dimer levels change over time?
Yes, D-dimer levels can fluctuate based on factors like age, pregnancy, recent surgery, or certain medications (e.g., steroids). If you’ve had a clot in the past, your baseline levels may be higher than someone without a history of clots. Always discuss your results with your healthcare provider.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy