LDH
An enzyme present in nearly every tissue that rises with cell damage anywhere in the body.
| Typical reference range | 120–250 U/L |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
Lactate dehydrogenase converts lactate and pyruvate during energy production and is found in the heart, liver, muscles, kidneys, lungs and blood cells.
Why it matters
LDH is a non-specific marker of tissue damage and cell turnover. It is used to help detect hemolysis, monitor some cancers (lymphoma, testicular cancer) and assess tissue injury.
What a high result can mean
Causes include hemolysis, muscle injury or strenuous exercise, liver disease, B12 or folate deficiency (ineffective red cell production), lung or heart damage, infections and some cancers. Hemolysis during blood draw falsely raises it.
What a low result can mean
Low LDH is rarely significant.
What affects the result
Very sensitive to sample handling; a hemolyzed sample can produce false highs. Recent intense exercise raises it. Isoenzyme testing can identify the tissue source if needed.
Units and conversion
Usually reported in U/L.
- From IU/L: multiply by 1 to get U/L
- From ukat/L: multiply by 60 to get U/L
Also called on lab reports
LD, Lactate Dehydrogenase, Lactic Acid Dehydrogenase, LDH, Total, LD, Total, Lactate Dehydrogenase (LD)
Related tests: Liver
This page is educational and does not replace advice from a healthcare professional.