Lactate Dehydrogenase (LDH) Test Test
The LDH test measures the level of lactate dehydrogenase in your blood or other body fluids. High levels can indicate tissue damage from disease, infection, or injury, but the test alone cannot pinpoint the cause or location.
What this test measures
A lactate dehydrogenase (LDH) test usually measures the level of lactate dehydrogenase (LDH) in a sample of your blood. In certain cases, LDH levels are measured in samples of other body fluids, such as cerebrospinal fluid, peritoneal fluid, or pleural fluid. LDH is an enzyme that helps your cells make energy and is found in almost all tissues, with the largest amounts in muscles, liver, kidneys, and red blood cells.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
Higher than normal LDH levels usually mean you have some type of tissue damage, often from disease, infection, or injury. However, high levels can also be caused by intense exercise, certain medicines (including aspirin), or if red blood cells broke open during sample collection.
Lower-than-normal results
Lower than normal LDH levels aren't common and usually aren't considered a health problem. They may be caused by taking large amounts of vitamin C or vitamin E, or by a rare genetic disorder called lactate dehydrogenase deficiency.
Frequently asked questions
What is an LDH test?
An LDH test measures the level of lactate dehydrogenase in your blood or other body fluids. LDH is an enzyme that helps your cells make energy.
Why is an LDH test done?
It is used to check for tissue damage from diseases, infections, or injuries. It can help diagnose or monitor conditions affecting the blood, liver, lungs, kidneys, heart, pancreas, brain, and certain cancers.
What does a high LDH level mean?
A high LDH level usually means you have some type of tissue damage. But it can also be caused by intense exercise, certain medicines, or problems with the blood sample.
What does a low LDH level mean?
Low LDH levels are rare and usually not a health problem. They may be caused by taking large amounts of vitamin C or E, or by a rare genetic disorder.
Can an LDH test diagnose a specific condition?
No, an LDH test alone cannot show what is damaging your tissues or where the damage is. It is usually done with other tests to help diagnose the problem.
Related lab tests
Sources
- MedlinePlus: Lactate Dehydrogenase (LDH) Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.