| Subject | Contents |
| Definition | A test that measures the amount of lactate dehydrogenase (LDH) in serum (see also LDH isoenzymes ). |
| Alternative Names | Lactate dehydrogenase; Lactic acid dehydrogenase |
| How the test is performed | Blood is drawn from a vein ( venipuncture ) or from a heel, finger, toe, or earlobe. The laboratory centrifuges the blood to separate the serum from the cells, and the LDH test is done on the serum. |
| How to prepare for the test | Your health care provider may advise you to withhold 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 evaluate the presence of tissue damage. The enzyme LDH is in many body tissues, especially the heart, liver, kidney, skeletal muscle , brain, blood cells, and lungs. LDH catalyzes the interconversion of pyruvate and lactate . Exercising muscles convert (and red blood cells metabolize ) glucose to lactate. Lactate is released into the blood and is eventually taken up by the liver. The liver converts lactate back to glucose and releases glucose into the blood. This glucose is then taken up by resting muscles, red blood cells, and other tissues. |
| Normal Values | 105 to 333 IU/L Note: IU/L = international units per liter Normal values may vary slightly from laboratory to laboratory. |
| What abnormal results mean | Greater-than-normal levels may indicate:cerebrovascular accident ( CVA , stroke )heart attackhemolytic anemiahypotensioninfectious mononucleosis intestinal ischemia (blood deficiency) and infarction (tissue death) liver disease (for example, hepatitis )muscle injury muscular dystrophy neoplastic (new abnormal tissue formation) states pancreatitis pulmonary infarction (tissue death) Note: if the LDH level is elevated, the health care provider will often recommend measurement of LDH isoenzymes . Additional conditions under which the test may be performed:anemia of B12 deficiencymegaloblastic anemiapernicious anemia |
| What the risks are | |
| Special considerations | |
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