Lactate Dehydrogenase (LDH) Activity in Serum/Plasma
This test measures the activity of the enzyme lactate dehydrogenase (LDH), which plays a role in energy production in cells. It helps identify conditions affecting cell damage or disease processes.
["LDH helps doctors assess damage to organs or tissues and certain health conditions."]
Key facts at a glance
- LOINC
- 2531-2
- Short code
- LDH Prt-cCnc
- Synonyms
- LDH Prt-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
Why Is This Test Done?
Doctors may order LDH testing to evaluate symptoms like fatigue, muscle weakness, or organ-related issues. It’s often used alongside other tests to diagnose conditions such as heart attacks, liver disease, muscle disorders, or certain cancers. LDH can also help monitor treatment progress or detect recurrence of diseases.
What Does a High or Low LDH Level Mean?
Elevated LDH levels may indicate damage to cells in organs like the heart, liver, kidneys, or lungs, or conditions such as anemia, infections, or certain cancers. Lower levels are less commonly significant but may sometimes reflect certain genetic or metabolic conditions.
Common Conditions Linked to LDH Levels
High LDH is frequently associated with conditions like myocardial infarction (heart attack), liver disease, muscle injuries, or blood cancers. It can also appear in infections, autoimmune diseases, or metabolic disorders.
Sample Collection and Preparation
A blood sample is typically drawn from a vein in your arm. The blood is processed to separate serum or plasma, which is then sent to the lab for testing. Avoid strenuous activity or eating heavy meals before the test to ensure accurate results.
Reference range
Adult: 140-280 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
LDH is a critical marker in diagnosing and managing diseases affecting cell integrity. It’s often used as part of a broader diagnostic panel to pinpoint the source of symptoms, guide treatment decisions, or monitor disease progression.
Short name
LDH Activity
Frequently asked questions
What Does It Feel Like to Get This Test?
How Often Should I Get This Test?
Can I Eat or Drink Before This Test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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