Lactate Dehydrogenase (LDH)
Lactate dehydrogenase (LDH) is an enzyme found in nearly every tissue in the body, including the liver, heart, muscles, and blood cells. It is released when cells are damaged.
Because LDH is so widespread, it is a general marker of cell turnover or tissue injury rather than a signal of one specific organ. It can support the assessment of many different conditions, which is why it is usually interpreted together with more targeted tests.
A higher LDH signals that cells somewhere in the body may be under stress or turning over faster, but because it comes from so many tissues, it cannot pinpoint the source on its own. Elevations can follow anything from muscle strain to blood cell breakdown. It is best read alongside other tests that narrow things down.
A low LDH is generally not a health concern and is not usually treated as significant.
Results are compared to your lab's reference range shown next to your value. Because LDH is so non-specific, your clinician will interpret it in the context of your other results and symptoms.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.