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.

Information about a laboratory test

LDH: High Result: What Does It Mean?

High LDH can occur with cell or tissue damage but does not identify the source; hemolysis, liver, muscle, lung and many other conditions can affect it.

Test summary

Test name: LDH
Abbreviations: LDH, LD
Category: Tissue Enzymes
Panel: Tissue Damage Assessment
Specimen: Serum / plasma
Common units: U/L, IU/L

What does the test measure?

The LDH test measures the blood level of lactate dehydrogenase, an enzyme present in many tissues.

Why is the test ordered?

It is used as a broad marker of possible tissue injury but does not identify the injured organ or cause by itself.

Information about a low result

A low value is usually not interpreted as a clinical problem by itself; the purpose of testing and laboratory context matter.

Information about a high result

High LDH can occur with cell or tissue damage but does not identify the source; hemolysis, liver, muscle, lung and many other conditions can affect 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 range 1

>= 125 – <= 220 U/L

Population: Adults / general laboratory example
Age range: 18
Specimen: Serum / plasma

Example LDH reference interval

This is sourced reference/clinical-context information and should not be used alone as a diagnosis or treatment decision. The laboratory report, medication use and clinical context take priority.

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

LDH can come from many tissues, and hemolysis of the blood sample can falsely increase it. Other tests and sometimes LDH isoenzymes are needed to localize the source.

Related specialties

Internal Medicine
Hematology
Gastroenterology
Emergency Medicine

Frequently asked questions

Sources

Creatine Kinase — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2023 · CK testing, muscle injury and CK isoenzyme context · Verified: Aug 12, 2026
Lactate Dehydrogenase (LDH) Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2023 · LDH testing and nonspecific tissue-damage interpretation · Verified: Aug 12, 2026
Lactate dehydrogenase test — U.S. National Library of Medicine (MedlinePlus)
Government medical encyclopedia · 2026 · Example 125–220 U/L LDH reference interval · Verified: Aug 12, 2026