Summary
| Direction in Long COVID | ↑ Elevated — higher than in the comparison group |
|---|---|
| Category | Coagulation |
| Also described as | Fibrin degradation product |
| Compared against | HC, R (healthy controls, recovered individuals without persistent symptoms) |
| Associated symptoms | Coagulopathy, thrombotic risk |
| Test type | Blood test (serum / plasma / whole blood) |
| LOINC code | 48065-7 |
| Source | Lai et al. 2023; Thomas et al. 2024 — doi:10.3389/fmed.2023.1085988 |
| Condition atlas | Long COVID Biomarker Atlas |
Other conditions where D-dimer is reported
- D-dimer in Atrial Fibrillation — ↑ elevated vs AF vs healthy/non-AF
See the cross-condition hub: D-dimer across conditions.
Trials, interventions and tests
In clinical-trial registrations this marker maps to the outcome term D-Dimer (11 registered trials use a matching outcome measure).
Clinical trials using D-dimer as an outcome
- NCT05890534: Pycnogenol® in Post-COVID-19 Condition (Completed)
Outcome measure: D-Dimer - NCT06766825: Study to Evaluate the Efficacy and Safety of Plitidepsin in Adults With Post-COVID-19 Condition (PCC) (Recruiting)
Outcome measure: To compare alterations in thromboinflammatory components (D-Dimer), among the three treatment arms. - NCT05877508: Anti-SARS-CoV-2 Monoclonal Antibodies for Long COVID (COVID-19) (Active Not Recruiting)
Outcome measure: D-Dimer - NCT05524532: Effects of Immulina TM Supplements With PASC Patients (Completed)
Outcome measure: Plasma D-Dimer, pg/mL - NCT05823896: ImPROving Quality of LIFe in the Long COVID Patient (Completed)
Outcome measure: Change from baseline in plasma biomarkers over time - NCT04482595: BIO 300 Oral Suspension in Previously Hospitalized Long COVID Patients (Unknown)
Outcome measure: Change in Clinical Laboratory Values - NCT04695704: Efficacy of Montelukast in Mild-moderate Respiratory Symptoms in Patients With Long-COVID-19: (Terminated)
Outcome measure: Factors of inflamatory and prothrombotic processes: D-Dimer, N-terminal prohormone of brain natriuretic peptide (NT Pro-BNP), C-reactive protenin and Antinuclear antibodies (ANA) - NCT06065033: Exercise Interventions in Post-acute Sequelae of Covid-19 (Withdrawn)
Outcome measure: D-dimer
3 more trials reference this marker.
Interventions studied alongside this marker
Hypothesis-generating links from trial outcome usage and literature co-occurrence. Not treatment recommendations.
- Paxlovid — 1 trial, 6 PubMed co-citations
e.g. Paxlovid plus glucocorticoids treatment in severe Omicron infected patients with hypoxaemia: A prospective… - Exercise therapy — 1 trial, 6 PubMed co-citations
e.g. Exercise-induced changes in hemostasis markers in marathon runners: effects of enzyme supplementation and…
Commercial test availability
D-dimer, Quantitative — commercial laboratory test.
Links are for reference only; availability, specimen requirements and coverage vary by location.
Related Coagulation markers in Long COVID
- Fibrinogen ↑
- PAI-1 ↑
- Amyloid-fibrin microclots ↑
- Platelet hyperactivation ↑
- Thrombin-antithrombin complex ↑
Full list: Long COVID Biomarker Atlas.
Frequently asked questions
Is D-dimer high or low in Long COVID?
Elevated. Studies summarised in the OSMF atlas report higher D-dimer in Long COVID than in healthy controls, recovered individuals without persistent symptoms. Source: Lai et al. 2023; Thomas et al. 2024.
What symptoms is D-dimer associated with in Long COVID?
The cited literature associates this marker with Coagulopathy, thrombotic risk. These are population-level associations and do not mean the marker causes the symptoms.
Which test measures D-dimer?
It is measured as a blood test (serum / plasma / whole blood). The standard laboratory code is LOINC 48065-7. Commercial laboratories such as Quest Diagnostics, LabCorp, Ulta Lab Tests list an orderable assay.
Is one abnormal D-dimer result diagnostic of Long COVID?
No. No single biomarker is diagnostic of Long COVID. D-dimer findings come from group comparisons, overlap considerably between patients and controls, and vary with study design, timing and comparison group. A result should be interpreted by a clinician alongside symptoms, history and other tests.
Is D-dimer specific to Long COVID?
No. The same marker is also reported in Atrial Fibrillation in this atlas, so it reflects shared biology (for example inflammation or vascular stress) rather than a condition-specific signature.
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Last reviewed: 2026-06-29 · Page generated from long-covid.json · Browse: Long COVID atlas · Biomarker Index · All marker pages
Disclaimer: This page is an educational synthesis of published, peer-reviewed research and is not medical advice. Biomarker findings vary across studies with case definitions, comparison groups, timing and assay methods. Direction of change reflects the predominant finding in the cited source and does not establish a diagnostic threshold. Discuss any test result with a qualified clinician.