LDH (Lactate Dehydrogenase) Test (LDH Fluid Test)

What is the lactate dehydrogenase or LDH Test?

Most body tissues like the brain, lungs, heart, and kidneys have LDH enzymes. An enzyme called lactate dehydrogenase supports our body's cellular respiration. The carbohydrates we consume are transformed into glucose and energy during cellular respiration. Usually, LDH remains inside the cell, but LDH is released into the bloodstream under abnormal conditions. In some instances of tissue injury, the enzyme remains elevated for up to 7 days in the bloodstream. The lactate dehydrogenase test or LDH test measures the level of lactate dehydrogenase enzyme in the blood.

When is the lactate dehydrogenase (LDH) test done?

A doctor may recommend checking Lactate dehydrogenase (LDH) for the following reasons:

• To check for any tissue damage

• To evaluate certain cancers

• To check the progress of the patients undergoing treatment for cancers

• To work on diseases affecting the liver or kidneys 

• To detect megaloblastic anaemias

• To detect bacterial or viral meningitis

What is the standard reference range for the lactate dehydrogenase or LDH blood test?

• Newborns :135 to 750 U/L (units/L)

• Children up to one year:180 to 435 U/L, 

• Above 18 years: 140 to 280 U/L.

How is the lactate dehydrogenase or LDH test done?

• The test requires a blood sample
• The test requires no fasting
• This test poses no risk to the patient.
• Results are usually reported within some hours after the blood is drawn.

LDH in any fluid sample will require fluid collection either by Lumbar puncture (CSF), Pleural tap (pleural fluid) and paracentesis (ascitic fluid).