Indicator Explainer
D-Dimer
A fibrin breakdown fragment — most useful for ruling out venous thromboembolism when clinical probability is low.
This page explains what the indicator is and how results are interpreted in general terms. Reference ranges depend on the laboratory, the method, and your own situation — no single “normal value” applies to everyone. This page is health information, not a diagnosis. For symptoms, treatment, or urgent concerns, contact a healthcare professional.
When it is tested
Measured in emergency pathways for suspected deep-vein thrombosis and pulmonary embolism, always in combination with validated clinical decision rules, and in some disseminated-intravascular-coagulation monitoring.
Reading results
A negative result on a validated assay is powerful for exclusion in low-probability patients; a positive result is common in the elderly, pregnant patients, post-operative and inflamed patients, and does not diagnose anything. Units (FEU vs DDU) and cutoffs differ between assays — including age-adjusted cutoffs — and must be read against the performing laboratory’s validation.
Questions to ask a professional
- Which clinical decision rule was applied before testing?
- Which units and cutoff does this assay use — and is an age-adjusted cutoff appropriate?
- What non-thrombotic causes of elevation apply to this patient?
References
- Lab Tests Online — D-Dimer
- Retrospective Evaluation of the D-Dimer in Patients Undergoing CTPA for PE Evaluation. — Acad Radiol, 2026-10-09 (PMID 42855383; literature)
- Association of plasma D-dimer and B-type natriuretic peptide levels with acute ischemic stroke mechanism, severity, and outcome. — Cerebrovasc Dis, 2026-10-09 (PMID 42853725; literature)
- Sex-specific hemostatic responses and alterations of Platelet Distribution Width (PDW) and D-dimer in mild COVID-19, Malaria, and co-infection in a tropical setting: A case-control study in Port Harcourt, Nigeria. — PLOS Glob Public Health, 2026-10-08 (PMID 42848813; literature)
- D-Dimer Dynamics as a Prognostic and Monitoring Biomarker in Triple-Negative and Metastatic Breast Cancer: A Narrative Review. — Breast Cancer (Dove Med Press), 2026-10-02 (PMID 42841024; literature)
- Iliofemoral Deep Vein Thrombosis Despite Repeatedly Negative D-Dimer Results. — Clin Case Rep, 2026-10-02 (PMID 42829551; literature)
- Association of D-dimer, fibrin degradation products, and coagulation parameters with progressive hemorrhagic injury following traumatic brain injury: A retrospective cohort study. — Medicine (Baltimore), 2026-10-01 (PMID 42854043; literature)
- The relationship between D-dimer and the risk for adverse outcomes in patients with heart failure. — Lab Med, 2026-10-01 (PMID 42832500; literature)