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 assess conditions affecting cell damage or metabolism.
["LDH helps diagnose and monitor conditions linked to cell injury or metabolic processes."]
Key facts at a glance
- LOINC
- 2535-3
- Short code
- LDH1 SerPl Chem Sepn-cCnc
- Synonyms
- LDH1 SerPl Chem Sepn-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
- Method
- chemical-separation
- 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 Is LDH Used For?
LDH is primarily used to identify and evaluate conditions that cause cell damage, such as heart attacks, muscle injuries, liver disease, or certain cancers. It can also help track the progression or response to treatment in these conditions.
How Is the Test Performed?
A blood sample is drawn from a vein, usually in the arm. The sample is then processed to measure LDH activity using specialized laboratory techniques.
Why Might My Doctor Order This Test?
Your doctor may recommend this test if you have symptoms like chest pain, muscle weakness, fatigue, or unexplained lab abnormalities. It can also be part of routine monitoring for chronic conditions.
What Are Possible Results?
Results are not provided in absolute numeric ranges here, as they vary by lab and condition. Elevated LDH levels may suggest tissue damage, while lower levels might indicate certain metabolic or genetic conditions.
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.
Elevated LDH levels can signal widespread cell damage, such as in heart attacks, muscle disorders, liver disease, or infections. Lower levels may be associated with specific genetic or metabolic disorders, but interpretation depends on clinical context and other test results. LDH is often used as a marker alongside other tests for diagnosis and management.
Short name
LDH Activity
Frequently asked questions
What Does an Elevated LDH Level Mean?
What Does a Low LDH Level Mean?
How Often Should I Get 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