Causes of High LDH

LDH samples of blood are usually sent to a laboratory for analysis. Save Jupiterimages / Polka Dot / Getty Images

Lactate dehydrogenase (LDH often abbreviated) is an enzyme found in almost all body tissues of plants and animals. In humans, this enzyme plays an important role in the conversion of glucose food into usable energy for cells reportedly KidsHealth. In normal lactate dehydrogenase levels in the blood they are low, so that high levels can indicate one of several medical conditions. The normal range of LDH is between 105 and 333 international units per liter, according to the National Institutes of Health.

Tissue damage

LDH tests may indicate tissue damage. Save test tubes image by Ruta Saulyte from

A doctor often orders an LDH test to determine whether the tissue has been damaged. When tissues are damaged by trauma or disease, increased amounts of enzyme LDH released into the bloodstream. While a DHL test can determine the presence of tissue damage, often more tests to assess the severity and location of the damage they are necessary. A test of LDH isoenzymes can be ordered to reduce the source and severity of cellular damage.

Hemolytic anemia

The rupture of red blood cells release high levels of LDH into the bloodstream. Save blood cells image by Marko Kovacevic from

Hemolytic anemia occurs when an abnormal breakdown of red blood cells is performed. Because LDH is abundant in red blood cells, a large number in the bloodstream can be a marker hemolyisis a medical term describing the destruction of red blood cells.

recent heart attack

Elevated levels of LDH may indicate a recent heart attack. Save heart attack image by JASON WINTER from

LDH levels rise after people suffer damage to the heart muscle by a heart attack. Usually, the LDH level rises 24 to 48 hours after this attack, then he reaches a peak two or three days and returned to normal after 10 to 14 days, according to the Florida Agency for Health administration.


LDH levels can confirm whether chemotherapy is working. Save look at that image by Keith Frith from

Many cancers can increase the level of LDH, although an elevated LDH can not identify a specific type of cancer. Because cancer cells have a high turnover rate, LDH levels increase due to the destroyed cells. LDH tests are often ordered in cancer patients as part of follow-up care to see if treatments are working.

Other conditions

Rough handling of blood samples can lead to false positive results. Save Hand and syringe with blood on a white background image by Aliaksandr Zabudzko from

Because LDH is found in the kidneys, liver, heart muscle, brain, lungs and red blood cells, high levels of LDH can indicate many other diseases, including viral meningitis, encephalitis, liver disease, lung disease, kidney disease and muscular dystrophy, to name a few. Certain drugs and strenuous exercise, however, can also raise levels of LDH in the blood. A sample of mishandled blood could appear as a false positive for high levels of LDH, due to the breakdown of red blood cells.