Can this result diagnose a condition on its own?

No. Laboratory results are interpreted with symptoms, medical history, specimen conditions and related tests.

Which reference range should I use?

Start with the performing laboratory's own reference interval; clinical cutoffs, when relevant, are separate sourced thresholds used for a specific purpose.

When should I discuss the result with a healthcare professional?

Results that are clearly outside range, persistent, symptomatic or unexpected should be reviewed by a healthcare professional. If you have emergency symptoms such as chest pain, severe shortness of breath, fainting, new neurologic symptoms or severe illness, seek urgent assessment rather than waiting for a laboratory result.

Information about a laboratory test

D-dimer: What Does This Test Measure?

The D-dimer test measures D-dimer, a fibrin breakdown fragment produced when clots are dissolved.

Test summary

Test name: D-dimer
Abbreviations: D-dimer
Category: Coagulation / Fibrinolysis
Panel: Thrombosis Assessment
Specimen: Citrated plasma
Common units: ng/mL FEU, µg/L FEU, mg/L FEU

What does the test measure?

The D-dimer test measures D-dimer, a fibrin breakdown fragment produced when clots are dissolved.

Why is the test ordered?

When clinical probability is appropriate, it is used to help rule out clotting disorders such as DVT or pulmonary embolism and can add information in conditions such as DIC.

Information about a low result

A low or normal D-dimer can help reduce the likelihood of a clot when pretest probability is appropriate; anticoagulants and test timing can affect the result.

Information about a high result

High D-dimer can occur when clot formation and breakdown are increased, but it does not prove that a clot is present; pregnancy, older age, recent surgery, inflammation and heart disease can also raise it.

Reference and clinical context

Start with the performing laboratory's reference interval, unit, specimen type and method. Numeric information on this page is stored as sourced example intervals or clinical thresholds.

Reference ranges may vary by laboratory, method used, age, sex, pregnancy status, and clinical context. The reference range on your own laboratory report takes precedence.

Interpretation notes

D-dimer is most useful when interpreted with clinical pretest probability. Cutoffs depend on assay and sometimes age, and physiologic elevations are common in pregnancy.

Related specialties

Emergency Medicine
Hematology
Internal Medicine
Pulmonology

Frequently asked questions

More information about this test

Sources

Fibrinogen blood test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2025 · Fibrinogen purpose and example 200–400 mg/dL reference interval · Verified: Aug 12, 2026
D-Dimer Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2024 · D-dimer use in clot assessment and non-thrombotic causes of elevation including pregnancy · Verified: Aug 12, 2026
Prothrombin Time Test and INR (PT/INR) — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2024 · PT/INR purpose, anticoagulation and coagulation interpretation · Verified: Aug 12, 2026
Partial Thromboplastin Time (PTT) Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2026 · aPTT/PTT purpose, prolonged and shortened result context · Verified: Aug 12, 2026