Lactate dehydrogenase (LDH) is a protein (enzyme) that speeds
up chemical reactions in the body. It is found in red blood cells and in many
organs, including the heart, liver, muscles, lungs, brain, and kidneys.
There are five different fractions of LDH (called isoenzymes): LDH-1,
LDH-2, LDH-3, LDH-4, and LDH-5.
A blood test to measure LDH levels
is done to check for damage to organs throughout the body. The amounts of each
isoenzyme also may be measured to help determine what organ may be damaged.
Some conditions that increase LDH levels include stroke, heart attack, anemia,