Blood Test for LDH

The LDH blood test is one way for doctors to detect the injury of tissues or the destruction of cells. LDH is also called "lactate dehydrogenase" or "lactic acid dehydrogenase."

LDH is an enzyme, a protein that helps chemical reactions to occur. It plays a role in the way your metabolism changes glucose into usable energy. It is not the job that LDH does as an enzyme that interests your doctor--rather, LDH is a useful test because cells release it when they die. A high level is a marker of tissue breakdown.

LDH is normally stored inside cells, and is only minimally present in the bloodstream. If cells that contain LDH are injured or inflamed, LDH leaks from cells and the level of LDH in the blood increases.

LDH is found in many organs and cells, including the:

- heart

- muscles

- liver

- red and white blood cells

- lungs

- kidneys

- stomach

- pancreas

- brain

- cancer cells.

Any of these tissues can release LDH when cells are breaking down.

This guide can help you understand how your doctor might interpret your LDH test result.