Lactate Dehydrogenase

This is a blood test to measure LDH, which is found in many tissues of the body. When these tissues are injured or damaged, the LDH becomes elevated. The LDH becomes elevated with liver disease or damage. There are different parts of the LDH called isoenzymes. Different isoenzymes come from different parts of the body. When specific isoenzymes are measured, it can be determined which organ is injured.

PREPARATION FOR TEST

No preparation or fasting is necessary. A blood sample is obtained by inserting a needle into a vein in the arm.

NORMAL FINDINGS

Adult/elderly: 100-190 U/L at 37° C (lactate pyruvate) or 100-190 U/L (SI units)

Isoenzymes:

  • Adult/elderly:

  • LDH-1: 17% to 27%

  • LDH-2: 27% to 37%

  • LDH-3: 18% to 25%

  • LDH-4: 3% to 8%

  • LDH-5: 0% to 5%

  • Child: 60-170 units/L (30° C)

  • Infant: 100-250 units/L

  • Newborn: 160-450 units/L at 30° C

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.

MEANING OF TEST

Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.

OBTAINING THE TEST RESULTS

It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.