Lactate Dehydrogenase (LDH) Activity in Serum/Plasma
This test measures the activity level of the enzyme lactate dehydrogenase (LDH) in your blood. LDH helps convert lactate into pyruvate and plays a role in energy production.
["LDH helps diagnose and monitor conditions affecting cells, such as heart attacks or muscle injuries."]
Key facts at a glance
- LOINC
- 2533-8
- Short code
- LDH Snv-cCnc
- Synonyms
- LDH Snv-cCnc
- Category
- chemistry
- Sample
- fluid
- Container
- Sterile tube
- 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
- 2-5 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h
- Hemolysis max
- 300
- TAT
- 4–24 hours
- Order
- routine
What Is LDH Used For?
LDH levels can help identify issues like heart damage (myocardial infarction), muscle injuries, liver disease, or certain cancers. Elevated LDH may suggest widespread cell damage or disease activity.
When Might You Need This Test?
Your doctor may order LDH if you have symptoms like chest pain, unexplained fatigue, or signs of organ damage. It’s also used in follow-up care for conditions like heart attacks, infections, or blood disorders.
How Is the Test Performed?
A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where LDH activity is measured using an enzymatic method.
What Do Results Mean?
Results are compared to a baseline or reference range for your age and health. High levels may indicate damage to cells in organs like the heart, liver, or muscles, while low levels are less common and may require further investigation.
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.
Clinical Significance: LDH is a sensitive marker for cell injury across multiple body systems. Elevated levels often correlate with conditions like myocardial infarction, hemolytic anemia, or severe infections, guiding treatment decisions and monitoring disease progression.
Short name
LDH Activity
Frequently asked questions
Why might my LDH levels be higher than usual?
How long does it take to get my LDH results?
Can lifestyle changes affect LDH levels?
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