Understanding LDH: Normal vs Optimal Ranges

?What is LDH?

Lactate dehydrogenase (LDH) is an enzyme found in virtually all body cells that converts pyruvate to lactate during anaerobic metabolism. When cells are damaged, LDH leaks into the bloodstream. It is a non-specific marker of cell damage across multiple organs including heart, liver, lungs, kidneys, and muscle.

!Why It Matters

While not specific for cardiac damage (superseded by troponin for MI), LDH remains clinically valuable for staging haematological malignancies (lymphoma), monitoring haemolytic anaemia, detecting liver damage, and as part of a non-specific injury panel. In COVID-19, markedly elevated LDH indicated severe lung injury and poor prognosis. The LDH isoenzyme pattern helps localise the source.

Reference Ranges

Lab normal ranges may vary between laboratories. Optimal and longevity targets are based on research literature and should be interpreted with your physician.

Symptoms of Imbalance

• Non-specific: fatigue, muscle pain depending on the underlying cause
• Symptoms of the underlying condition (leukaemia, liver disease, haemolysis)

How to Improve Your Levels

• 1Identify and treat the underlying cause of elevation
• 2Monitor trends — LDH falls as acute injury resolves
• 3Avoid excessive muscle damage (rhabdomyolysis) through progressive exercise training

When to Test

Haematological malignancy staging; haemolysis evaluation; monitoring liver or muscle disease; COVID-19 severity assessment.

Related Biomarkers