biotech Lab Marker

LDH Blood Test: What Your Results Mean

LDH (lactate dehydrogenase) is an enzyme found in nearly every cell in the body. It plays a role in energy production by converting lactate to pyruvate. When cells are damaged or destroyed, they release LDH into the bloodstream. Because LDH is non-specific — present in the heart, liver, kidneys, red blood cells, muscles, lungs, and brain — an elevated result signals tissue damage somewhere in the body, and additional tests are needed to identify the source.

check_circle

Normal Range

140 – 280 U/L

science

Unit

U/L

What Your Results Mean

Normal

A normal LDH level indicates minimal cell damage or tissue breakdown. Cells throughout the body are intact and not releasing significant amounts of this enzyme into the circulation.

High

Elevated LDH indicates tissue damage or cell destruction. Common causes include heart attack (though troponin is more specific), haemolytic anaemia (red blood cell destruction), liver disease, pulmonary embolism, muscle injury (including rhabdomyolysis), kidney infarction, and many cancers — particularly lymphoma, leukaemia, and metastatic tumours. LDH is widely used as a cancer marker and prognostic indicator.

Low

Low LDH is not clinically significant and is not associated with any recognised disease. It may be seen in individuals with very low muscle mass.

Frequently Asked Questions

What does high LDH mean? expand_more
High LDH is a non-specific marker of cell damage. It can be elevated in heart attack, haemolytic anaemia, liver disease, pulmonary embolism, muscle breakdown, kidney disease, and cancer. Additional tests — such as a complete metabolic panel, cardiac enzymes, or imaging — are required to determine the source.
Why is LDH used in cancer management? expand_more
LDH is released when tumour cells grow rapidly and die. In cancers such as lymphoma, leukaemia, and melanoma, LDH is used as a prognostic marker — higher levels generally indicate more aggressive disease and worse prognosis. It is also used to monitor response to treatment.
What is the normal LDH level? expand_more
Normal LDH ranges from approximately 140 to 280 U/L, though reference ranges vary by laboratory and assay method. Age and sex also influence values. Always compare to the reference range provided by the laboratory that ran your test.
Can exercise raise LDH levels? expand_more
Yes. Intense physical exercise causes muscle cell damage and releases LDH, CK, and other muscle enzymes into the blood. LDH typically rises after strenuous exercise and normalises within 24 to 72 hours. Avoid heavy exercise in the 48 hours before an LDH test if possible.
biotech

Have a lab test? Get AI-powered results in minutes.

Upload your lab report and receive a detailed, plain-language explanation of every marker.

upload_file Analyse My Results