What Is an LDH Blood Test?

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A lactate dehydrogenase, or LDH, blood test is a test that determines the blood LDH level, according to MedlinePlus. Typically, it is used to check if tissue is damaged. Doctors may also perform this test to check for anemia and cancers such as leukemia and lymphoma.

The LDH is an enzyme that speed up the breakdown of sugar into energy to be used in the body cells, explains Healthline. It is divided into five types: LDH-1, LDH-2, LDH-3, LDH-4 and LDH-5. LDH occurs in various body tissues and organs such as the brain, heart, liver, kidney, pancreas and skeletal muscles.

To perform LDH test, a doctor first draws a blood sample from a patient’s blood vessel using a needle, says MedlinePlus. The doctor then takes the sample to the lab for examination. Before the test, the doctor may advise the patient not to take specific medications, such as aspirin, fluorides, procainamide, narcotics and mithramycin as they may lead to inaccurate results. Additionally, obtaining a blood sample may be risky as it may cause infection due to skin breakage, excessive bleeding or lightheadedness.

Normal LDH test results range from 105 to 333 international units per liter, although this may vary from one lab to another due to sample and measurement variations among laboratories, as MedlinePlus notes. Abnormal results may be a sign of conditions such as heart attack, liver disease, stroke, pancreatitis and muscle injury.