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Lactate Dehydrogenase (LDH)

Published: July 27, 2026Updated: August 25, 2026

LDH is an enzyme found in almost all body tissues, and its levels in the blood can indicate tissue damage or disease. It is particularly useful in diagnosing and monitoring cardiovascular conditions.

Quick summary

LDH is a blood enzyme that signals tissue damage or disease, especially in cardiovascular conditions.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
U/L
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
FDA Cleared Cardiovascular Assay
interpretation: {"text":"140–280 U/L: LDH levels within this range are generally considered normal.","label":"Normal"}; {"text":">280 U/L: Elevated LDH levels may indicate tissue damage, such as in heart attacks or other cardiovascular events.","label":"Elevated"}

Lactate dehydrogenase (LDH) is an enzyme that catalyzes the conversion of lactate to pyruvate and is found in various tissues throughout the body, including the heart, liver, and muscles. Elevated levels of LDH in the blood can indicate tissue damage or disease.

In the context of cardiovascular health, LDH levels can be used to diagnose and monitor conditions such as myocardial infarction (heart attack), congestive heart failure, and pulmonary embolism. The enzyme is released into the bloodstream when heart tissue is damaged.

While LDH is a useful diagnostic tool, it is not specific to any one condition. Therefore, it is often used in conjunction with other tests to provide a more comprehensive understanding of a patient's health status.

Frequently asked questions

What conditions can cause elevated LDH levels?
Elevated LDH levels can be caused by a variety of conditions, including heart attacks, liver disease, anemia, and certain types of cancer.
Is LDH testing specific for cardiovascular disease?
No, LDH testing is not specific for cardiovascular disease. It indicates tissue damage but does not pinpoint the exact cause.
  1. 1
    Mayo Clinic: Lactate Dehydrogenase (LDH) TestSource
  2. 2
    American Heart Association: Heart AttackSource

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 25, 2026. · Read our editorial policy