What is the Lactate Dehydrogenase (LDH) test?

The Lactate Dehydrogenase (LDH) blood test measures the level of LDH, an enzyme found in almost all body tissues, including the heart, liver, lungs, muscles, kidneys and blood cells. LDH plays a role in energy production within cells.

When cells are damaged or destroyed, LDH is released into the bloodstream. Elevated LDH levels therefore indicate tissue injury, inflammation, hypoxia or increased cell turnover, rather than damage to a single specific organ.

Because LDH is non-specific, it is usually interpreted alongside other tests to help pinpoint the underlying cause.

Why do I need a Lactate Dehydrogenase test?

LDH testing helps detect and monitor conditions involving cell damage or breakdown, especially when symptoms are unclear or multiple organs may be involved.

You may need an LDH test if you:

• Have unexplained fatigue or weakness
• Have suspected tissue or organ damage
• Are being investigated for anaemia or haemolysis
• Have liver, lung or muscle disease
• Are being monitored for cancer or inflammation
• Have infection or inflammatory conditions
• Have abnormal results on other blood tests

Conditions associated with raised LDH include:

• Tissue injury or trauma
• Haemolytic anaemia
• Liver disease
• Lung disease or pneumonia
• Muscle injury
• Certain cancers
• Severe infections

Benefits of the Lactate Dehydrogenase test

• Detects tissue damage
  Indicates cell injury or breakdown.
• Broad clinical utility
  Reflects multiple organ systems.
• Supports investigation of unexplained symptoms
  Useful when diagnosis is unclear.
• Assists in anaemia evaluation
  Elevated in haemolysis.
• Used in cancer monitoring
  Reflects tumour burden or progression.
• Clinically established enzyme test
  Widely used in hospital and outpatient care.
• Helpful in infection and inflammation assessment
  Indicates severity in some conditions.
• Simple blood test
  Requires only one sample.

Step by step – how the test works

You can access Lactate Dehydrogenase testing UK-wide through two options:

1. Clinic appointment
   Attend your nearest UK clinic where a healthcare professional will take your blood sample.
2. At-home or hotel visit (£60 extra)
   A qualified phlebotomist comes to your home or hotel.

Your sample is analysed in an accredited UK laboratory and results are delivered securely.

Your results explained

Low LDH levels

Generally not clinically significant.

Typical UK interpretation:

• Below reference range

Normal LDH levels

Suggest no significant tissue damage or cell breakdown.

Typical UK interpretation:

• 140–280 U/L (range may vary by laboratory)

High LDH levels

Indicate tissue damage, inflammation or increased cell turnover.

Typical UK interpretation:

• Above laboratory reference range

LDH must be interpreted alongside other tests and clinical findings.