Skip to content

Lactate Dehydrogenase [Catalytic Activity/Volume] in Serum or Plasma

Published: August 9, 2026Updated: August 17, 2026

This blood test measures the activity of lactate dehydrogenase, an enzyme found in many body tissues. It is most useful as a general marker of cell or tissue injury and is often interpreted alongside other laboratory results.

Quick summary

["Elevated LDH may indicate cell or tissue injury, but the result must be interpreted with symptoms, examination findings, and other tests."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
2532-0
Short code
LDH SerPl-cCnc
Synonyms
LDH SerPl-cCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
140
Ref high
280
Critical range
— – 1000 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
83615
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Does the LDH Test Measure?

LDH is an enzyme that helps cells convert energy-related compounds. When cells are damaged, LDH can be released into the bloodstream, increasing the measured enzyme activity in the blood sample.

Why Is This Test Performed?

Clinicians may order an LDH test to help evaluate unexplained symptoms, monitor certain conditions, or assess possible tissue injury. The test is interpreted with other findings because LDH is not specific to one organ or disease.

What Can Cause an Elevated LDH Level?

Moderate increases can occur with conditions affecting the heart, liver, skeletal muscles, kidneys, or blood cells. More substantial elevations may occur with widespread tissue injury, certain cancers, infections, or hemolysis, which is the breakdown of red blood cells.

What Influences the Result?

Exercise, recent injections, trauma, pregnancy, and blood-sample handling can affect LDH levels. Hemolysis in the sample may falsely increase the result, so the laboratory may repeat the test if the specimen appears damaged.

Reference range

Adult: 140-280 U/LN/A

Specimen: serum

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated LDH level is not diagnostic by itself. It can indicate tissue injury or increased cell turnover, and its clinical meaning depends on the cause, severity, trend over time, and results of other tests. A sudden rise in LDH after symptoms suggesting a heart attack may support prompt medical evaluation, but it does not confirm that diagnosis.

Short name

LDH test

Frequently asked questions

Does a high LDH level mean I have cancer?
No. Many noncancerous conditions, including tissue injuries, infections, liver or muscle disorders, and hemolysis, can raise LDH. Cancer is only one possible cause and must be evaluated using symptoms, imaging, and other laboratory findings.
Why might my LDH result be high with no symptoms?
Mild increases may reflect recent strenuous exercise, minor trauma, injections, or laboratory-related factors such as hemolysis. Your clinician can determine whether the result is meaningful and whether repeat testing is appropriate.
Can LDH levels be low?
Yes, although low results are less commonly clinically important. Very low activity can occur in a few inherited or medication-related circumstances. The result should still be interpreted in the context of the laboratory's measurement method and your overall condition.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy