Biochemistry

Lactate Dehydrogenase (LDH)

Normal Range
Fluid level < 2/3 the upper limit of normal serum LDH
Sample Type
Standard
Fasting
No
Unit
U/L

Lactate Dehydrogenase is an intracellular enzyme that catalyzes the conversion of lactate to pyruvate. It is found in nearly all tissues. In Fluid Biochemical Analysis (e.g., pleural or ascetic fluid), LDH levels are used to apply 'Light's Criteria' to differentiate between a transudate (usually systemic cause like heart failure) and an exudate (local cause like infection or malignancy). High fluid LDH is indicative of local tissue damage or inflammation.

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Interactive
U/L

Enter your lab result to see where you stand compared to the standard reference range.

Why Context Matters

LDH is extremely sensitive to sample handling. If the fluid sample is even slightly hemolyzed (red blood cells rupture), the LDH will be falsely elevated, leading to a potential misdiagnosis of an exudate.

Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.

Clinical References

Source-of-truth databases and clinical guidelines for Lactate Dehydrogenase (LDH):

Related Indicators

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Medically Reviewed by Dr. Binoy Babu, MBBS

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Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.

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