Lactate dehydrogenase test

Definition

The lactate dehydrogenase (LDH) test measures the amount of LDH in the blood.

See also: LDH isoenzymes

Alternative Names

LDH test; Lactic acid dehydrogenase test

How the test is performed

A blood sample is needed. For information on how this isdone, see: Venipuncture

How to prepare for the test

Your health care provider may ask you to stop taking drugs that may affect the test. Drugs that can increase LDH measurements include anesthetics, aspirin, clofibrate, fluorides, mithramycin, narcotics, and procainamide.

How the test will feel

Why the test is performed

LDH is most often measured to check for tissue damage. The protein LDH is in many body tissues, especially the heart, liver, kidney, muscles, brain, blood cells, and lungs.

Other conditions under which the test may be done:

• Anemia of vitamin B-12 deficiency
• Leukemia or lymphoma
• Megaloblastic anemia
• Pernicious anemia

Normal Values

A typical range is 105 - 333 IU/L (international units per liter).

The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

Higher-than-normal levels may indicate:

• Blood flow deficiency (ischemia)
• Cerebrovascular accident (such as a stroke)
• Heart attack
• Hemolytic anemia
• Infectious mononucleosis
• Liver disease (for example, hepatitis)
• Low blood pressure
• Muscle injury
• Muscular dystrophy
• New abnormal tissue formation (usually cancer)
• Pancreatitis
• Tissue death

If the LDH level is raised, your doctor may order an LDH isoenzymes test.

What the risks are

Special considerations

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References

Gallagher PG. Hemolytic anemias:  red cell membrane and metabolic defects In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 164.

Gregg X, Prchal JT. Red Blood Cell Enzymopathies. In: Hoffman R, Benz EJ, Shattil SS, et al, eds. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2008:chap 45.