An LDH (Lactate Dehydrogenase) test measures the level of LDH enzyme in the blood. This enzyme is found in many tissues, including the heart, liver, muscles, kidneys, lungs, and blood cells. When any of these tissues are damaged, LDH levels rise. Doctors recommend this test to help detect conditions such as liver disease, muscle injury, anemia, lung disorders, heart issues, or certain infections. Elevated LDH can indicate tissue damage but does not specify the exact location, so it is usually interpreted along with other tests.

For the LDH test, a small blood sample is collected from a vein, and no fasting or special preparation is needed. This test helps monitor ongoing diseases, evaluate tissue damage, and track recovery. LDH is also used in assessing conditions like hemolysis, pancreatitis, and some cancers where cell breakdown increases LDH levels.