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Lactate dehydrogenase or LD is an enzyme present in all cells. The myocardium and skeletal muscles, red blood cells, and liver and kidney tissue contain the largest quantities of the LD enzyme. Lactate dehydrogenase normally exists within cells and is only present in the bloodstream in small quantities. It is released into the bloodstream when tissue cells are damaged or destroyed. For this reason, LD has been used as a general indicator of tissue damage. However, it does not specify which tissue has been damaged or what has caused the damage.

LD occurs in slightly different versions in different types of tissue. The source of the damage can be determined more precisely by measuring the concentrations of the various forms of LD.

When should LD be measured?

LD can be measured as a supplementary test when suspecting damage or a disorder of the heart, liver, kidneys, skeletal muscle, brain, or lungs.

An LD test can be carried out in connection with a muscle injury, diagnosed cancer, fatigue, headaches, tinnitus, or heart palpitations.

What does an LD test measure?

An LD test is carried out when suspecting damage or a disorder of the tissue, particularly in the heart, liver, kidneys, skeletal muscles, brain, or lungs. However, the LD test does not indicate specific tissue damage but requires additional tests. Moreover, LD levels can be checked when monitoring certain types of cancer, such as lymphoma, leukaemia, melanoma, testicular cancer, or ovarian cancer.

Normally, the result is:

Reference values:

  • Under 68-year-olds: 105–205 U/l
  • Over 68-year-olds: 115–255 U/l

The LD levels increase in the final trimester of pregnancy.

Please contact your physician or other healthcare professional if you suspect an illness or need help interpreting the results.

Read more about defining reference values.

The LD levels can be increased by:

  • Disorders of the myocardium
  • Liver disorders, such as hepatitis and liver cirrhosis
  • Lung disorders, such as pulmonary embolism and sarcoidosis
  • Malignant tumours
  • Muscle and kidney disorders
  • Haematological disorders such as megaloblastic and haemolytic anaemia, acute leukaemia, lymphomas.
  • Various blood cell disorders such as megaloblastic and haemolytic anaemia, acute leukaemia, lymphomas.

A low LD value is not clinically significant. Excessive consumption of vitamin C may sometimes cause low LD values.

SYNLAB test list: Lactate dehydrogenase (2194 S-LD) https://www2.synlab.fi/laboratoriokasikirja/tutkimuskuvaukset/laktaattidehydrogenaasi/

Lab Tests Online: Lactate Dehydrogenase (LD) https://labtestsonline.org/tests/lactate-dehydrogenase-ld


Fasting is not required

This examination does not require fasting