This test measures the level of lactate dehydrogenase (LDH), also known as lactic acid

dehydrogenase, in your blood or sometimes in other body fluids. LDH is a type of protein,

known as an enzyme. LDH plays an important role in making your body's energy. It is found

in almost all the body's tissues, including those in the blood, heart, kidneys, brain, and

lungs.When these tissues are damaged, they release LDH into the bloodstream or other body

fluids. If your LDH blood or fluid levels are high, it may mean certain tissues in your body

have been damaged by disease or injury.