The LDH (lactate dehydrogenase) blood test measures the level of LDH in your blood. LDH is an enzyme in many body organs and tissues, including the heart, liver, muscles, and red blood cells. The LDH test is often used to help diagnose and monitor various medical conditions, such as anemia, heart attack, and liver disease. It may also be ordered to check for tissue damage or monitor treatment effectiveness for specific conditions. Since lactic dehydrogenase is present in many body tissues, its diagnostic usefulness is limited. Tissue specificity may be enhanced by LDH isoenzyme analysis.

The GGT bood test looks for an enzyme, or protein, called gamma-glutamyl transpeptidase (GGT) in your blood. GGT is found in liver cells. This test helps your doctor look for possible damage to your liver or its ducts. It can also help tell the difference between liver and bone disease if your results from a different blood test called alkaline phosphatase are abnormal. Higher than normal test results could be a sign of liver damage from diseases such as hepatitis, cirrhosis, tumors, or pancreatic cancer. But a higher than normal GGT level does not tell you the specific cause of liver disease or damage.