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Lactate Dehydrogenase (LDH)

Blood Sciences Test



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Reference Range

Reference Ranges from 15th December 2020:

If analysis performed before this date please contact us for reference ranges


Up to 21 days:                      225 – 600 U/L

21 days up to 16 years:       120 – 300 U/L

Adults (16 years and above)

Females:                                135 – 214 U/L

Males:                                    135 – 225 U/L

Test Usage

LDH is a very non-specific enzyme which is present in virtually all cells. An elevated level by itself is unlikely, therefore, to indicate which organ is involved, or what the disease process may be. It can be useful, however, with knowledge of patient’s clinical presentations and proposed or established diagnoses.

New LDH Method from 15th December 2020

The method that we use for measuring LDH has changed. This was due to a change made by the test manufacturer (Roche). This change occurred on 15th December 2020. The new method produces results that are approximately 45% lower than on the previous LDH method. Please take account of this when making comparisons between LDH values before and after this date. For example, an LDH of 300 U/L measured before the change would be equivalent to 165 U/L measured after the change. The reference intervals have been adjusted to reflect this change.  The results of our in-house method comparison are below:

LDH Concentration (U/L) Number Tested: Mean bias (U/L): Bias %
Low: 0.0 to 300.00 10 -111.40 -43.7
Mid: 300 to 500.00 47 -173.40 -44.0
High: 500 to 1600.00 18 -313.4 -43.2


Turnaround Time

1 day


Local test

Can be added on to an existing request up to 12 hours following sample receipt

Specimen Labelling Procedure
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