The lactate dehydrogenase (LDH) test measures the amount of LDH in the blood.
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
Your health care provider may ask you to stop taking certain medicines that may affect the test. Medicines that can increase LDH measurements include anesthetics, aspirin, clofibrate, fluorides, mithramycin, narcotics, and procainamide. If you take any of these, tell your provider before the test is ordered.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.
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 for which the test may be done include:
Normal value range is 105 - 333 IU/L (international units per liter).
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 results.
What Abnormal Results Mean
A higher-than-normal level may indicate:
- Blood flow deficiency (ischemia)
- Heart attack
- Hemolytic anemia
- Infectious mononucleosis
- Liver disease (for example, hepatitis)
- Low blood pressure
- Muscle injury
- Muscle weakness and loss of muscle tissue (muscular dystrophy)
- New abnormal tissue formation (usually cancer)
- Tissue death
If the LDH level is raised, your doctor may order an LDH isoenzymes test to determine the location of any tissue damage.
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
LDH test; Lactic acid dehydrogenase test
Ferri FF, ed. Ferri's Clinical Advisor 2014. Philadelphia: Pa: Elsevier Mosby; 2014: Section IV– Laboratory tests and interpretation of results.
Update Date 2/24/2014
Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.