Prostate Cancer Screening: When to Test & What to Expect After Diagnosis

Lactate dehydrogenase, commonly known as LDH, is an enzyme found in nearly all body tissues. It plays a crucial role in converting sugar into energy that cells can use. When cells are damaged or destroyed, LDH is released into the bloodstream, making it a useful marker for detecting tissue damage. The LDH blood test measures the amount of this enzyme in your blood and can help healthcare providers identify and monitor various medical conditions.

An LDH test may be ordered when a person shows signs of tissue damage or cell destruction. Common symptoms that might prompt this test include unexplained fatigue, weakness, pale skin, shortness of breath, or abdominal pain. The test is frequently used to help diagnose conditions such as anemia, liver disease, muscle injury, heart attack, or certain types of cancer. It can also be valuable in monitoring the progression of diseases and evaluating how well treatment is working, particularly in cases of cancer or hemolytic anemia.

The LDH test is performed using a simple blood sample, typically drawn from a vein in your arm. No special preparation is usually required, though your healthcare provider may ask you to avoid strenuous exercise before the test, as physical activity can temporarily raise LDH levels. The blood sample is then sent to a laboratory where it is analyzed to determine the concentration of LDH enzyme present.

Normal LDH levels generally range from 140 to 280 units per liter, though this can vary slightly depending on the laboratory and testing methods used. Elevated LDH levels indicate that tissue damage has occurred somewhere in the body, but the test alone cannot pinpoint the exact location or cause. High levels can result from various conditions including heart attack, stroke, liver disease, certain types of anemia, muscular dystrophy, pancreatitis, kidney disease, meningitis, encephalitis, HIV, or cancer. Because LDH is found throughout the body, additional tests are usually needed to determine the specific source of the elevation and make an accurate diagnosis. Your healthcare provider will interpret your results in the context of your symptoms, medical history, and other diagnostic findings.