Summary
| Direction in Long COVID | ↑ Elevated — higher than in the comparison group |
|---|---|
| Category | Metabolic |
| Also described as | Tissue damage marker |
| Compared against | HC (healthy controls) |
| Associated symptoms | Tissue injury |
| Test type | Blood test (serum / plasma / whole blood) |
| LOINC code | 2532-0 |
| Source | Kallaste et al. 2025 — doi:10.3390/medicina61060996 |
| Condition atlas | Long COVID Biomarker Atlas |
Trials, interventions and tests
In clinical-trial registrations this marker maps to the outcome term Assessment of Change in Lactate dehydrogenase (LDH) Laboratory Testing Results (3 registered trials use a matching outcome measure).
Clinical trials using LDH (Lactate dehydrogenase) as an outcome
- NCT07046208: Effects os Physiotherapeutic Rehabilitation on Function Autonomic and Inflammatory in Patients With Long Covid (Not Yet Recruiting)
Outcome measure: Inflammation - NCT04482595: BIO 300 Oral Suspension in Previously Hospitalized Long COVID Patients (Unknown)
Outcome measure: Change in Clinical Laboratory Values for Serum Enzymes - NCT05669261: Treatment of Long COVID Symptoms Utilizing Autologous Stem Cells Following COVID-19 Infection (Unknown)
Outcome measure: Assessment of Change in Lactate dehydrogenase (LDH) Laboratory Testing Results
Commercial test availability
Lactate dehydrogenase (LDH) — commercial laboratory test.
Links are for reference only; availability, specimen requirements and coverage vary by location.
Related Metabolic markers in Long COVID
- Vitamin D (25-OH) ↕
- Carnitine / Acylcarnitines ↕
- Lactate ↑
- 4-Aminobutanoate (GABA) ↑
- Xanthine ↑
- Thymine ↓
- Uracil ↓
- Porphobilinogen ↑
Full list: Long COVID Biomarker Atlas.
Frequently asked questions
Is LDH (Lactate dehydrogenase) high or low in Long COVID?
Elevated. Studies summarised in the OSMF atlas report higher LDH (Lactate dehydrogenase) in Long COVID than in healthy controls. Source: Kallaste et al. 2025.
What symptoms is LDH (Lactate dehydrogenase) associated with in Long COVID?
The cited literature associates this marker with Tissue injury. These are population-level associations and do not mean the marker causes the symptoms.
Which test measures LDH (Lactate dehydrogenase)?
It is measured as a blood test (serum / plasma / whole blood). The standard laboratory code is LOINC 2532-0. Commercial laboratories such as Quest Diagnostics, LabCorp, Ulta Lab Tests list an orderable assay.
Is one abnormal LDH (Lactate dehydrogenase) result diagnostic of Long COVID?
No. No single biomarker is diagnostic of Long COVID. LDH (Lactate dehydrogenase) 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.
Cite this page
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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.