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LD

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Also known as: LDH
Formal name: Lactate Dehydrogenase

At a Glance

Why Get Tested?

To help detect a condition causing tissue damage, such as a blood or liver disease, and to monitor its progress; to help stage, determine prognosis, and/or response to treatment of certain cancers; to help evaluate body fluid (other than blood)

When to Get Tested?

Along with other tests, when a health practitioner suspects that you have an acute or chronic condition that is causing tissue or cellular destruction; sometimes when you have been diagnosed with cancer; when you have symptoms of meningitis or have fluid accumulation in a specific part of your body

Sample Required?

A blood sample drawn from a vein in your arm; sometimes a special procedure may be performed to collect a sample of body fluid from an affected area of the body

Test Preparation Needed?

None

The Test Sample

What is being tested?

Lactate dehydrogenase (LD or LDH) is an enzyme involved in energy production that is found in almost all of the body's cells, with the highest levels found in the cells of the heart, liver, muscles, kidneys, lungs, and in blood cells; bacteria also produce LD. This test measures the level of LD in the blood or sometimes other body fluids.

Blood LD
Only a small amount of LD is usually detectable in the fluid portion of the blood (serum or plasma). LD is released from the cells into the serum when cells are damaged or destroyed. Thus, an LD blood level is a non-specific marker for the presence of tissue damage somewhere in the body. By itself, it cannot be used to identify the underlying cause or location of the cellular damage. However, it may be used, in conjunction with other blood tests, to help evaluate for and/or monitor conditions that lead to tissue damage, such as liver or blood diseases or cancer.

Fluid LD
Sometimes when there is injury, inflammation, or infection within a specific area of the body, such as the brain, heart or lungs, fluid will accumulate or constituents of the fluid present will change. The level of LD present in the fluid may be useful in determining the cause. For example, LD is typically high in cerebrospinal fluid when an individual has bacterial meningitis. The LD test can also be used, along with other tests, to determine whether fluid accumulation, for example around the heart or lungs or in the abdominal cavity, is due to injury or inflammation (exudate) or due to an imbalance of fluid pressure inside blood vessels and the protein level in blood (transudate). The article on Body Fluid Analysis lists some fluids that may be evaluated using an LD test.

How is the sample collected for testing?

A blood sample is obtained by inserting a needle into a vein in the arm. Sometimes a special procedure may be performed to collect body fluid from the site affected (e.g., cerebrospinal fluid, pleural fluid, peritoneal fluid, etc.).

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

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Article Sources

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

Sources Used in Current Review

Gersten, T. (Updated 2012 February 8). Lactate dehydrogenase test. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003471.htm through http://www.nlm.nih.gov. Accessed July 2014.

(© 1995–2014) Lactate Dehydrogenase (LD), Serum. Mayo Clinic Mayo Medical Laboratories [On-line information]. Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/8344 through http://www.mayomedicallaboratories.com. Accessed July 2014.

Dugdale, D. (Updated 2013 January 26). LDH isoenzymes. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003499.htm through http://www.nlm.nih.gov. Accessed July 2014.

Gardner, T. and Berk, B. (Updated 2013 September 3). Acute Pancreatitis. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/181364-overview through http://emedicine.medscape.com. Accessed July 2014.

(Updated 2013 June 3). Acute Pericarditis. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/156951-overview through http://emedicine.medscape.com. Accessed July 2014.

Dowshen, S. (Reviewed 2011 March). Blood Test: Lactate Dehydrogenase (LDH). KidsHealth from Nemours [On-line information]. Available online at http://kidshealth.org/parent/system/medical/test_ldh.html through http://kidshealth.org. Accessed July 2014.

Pagana, K. D. & Pagana, T. J. (© 2011). Mosby's Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 603-605.

Clarke, W., Editor (© 2011). Contemporary Practice in Clinical Chemistry 2nd Edition: AACC Press, Washington, DC. Pp 313.

McPherson, R. and Pincus, M. (© 2011). Henry's Clinical Diagnosis and Management by Laboratory Methods 22nd Edition: Elsevier Saunders, Philadelphia, PA. Pp 292-294.

Strimel, W. (Updated 2014 April 27). Pericardial Effusion. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/157325-overview through http://emedicine.medscape.com. Accessed July 2014.

Rubins, J. (Updated 2013 November 18). Pleural Effusion. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/299959-overview through http://emedicine.medscape.com. Accessed July 2014.

Sources Used in Previous Reviews

Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].

Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.

Lactate Dehydrogenase. ARUP's Guide to Clinical laboratory Testing [On-line information]. Available online at http://www.aruplab.com/guides/clt/tests/clt_a32b.htm#1140532 through http://www.aruplab.com.

(2002 October 25, Updated). LDH isoenzymes. MEDLINEplus Health Information [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003499.htm.

(2001 November 20, Updated). LDH. MEDLINEplus Health Information [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003471.htm.

Spengler, R. (2002 May 14, Updated). What is lactate dehydrogenase (LDH)? St. Joseph's Hospital, Health Library, Medical Tests [On-line information]. Available online at http://www.sjo.org/library/healthguide/MedicalTests/topic.asp?hwid=tv6793abc through http://www.sjo.org.

Martin, G. (1998 March 9). The Obsolescence of Lactate Dehydrogenase Testing. American Medical Association, Archives of internal Medicine, Editor's Correspondence, Vol. 158 No. 5 [On-line information]. Available online at http://archinte.ama-assn.org/issues/v158n5/ffull/ilt0309-4.html through http://archinte.ama-assn.org.

Spengler, R. (2002 May 14, Updated). Cardiac Enzyme Studies. WebMD [On-line information]. Available online at http://my.webmd.com/printing/article/1675.55521 through http://my.webmd.com.

Lactate dehydrogenase isoenzymes test. Hendrick Health System, AccessMed Health Information Library [On-line information]. Available online at http://www.hendrickhealth.org/healthy/00054240.html through http://www.hendrickhealth.org.

Lactate dehydrogenase test. Hendrick Health System, AccessMed Health Information Library [On-line information]. Available online at http://www.hendrickhealth.org/healthy/00054250.html through http://www.hendrickhealth.org.

Pagana, Kathleen D. & Pagana, Timothy J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 581-582.

Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry, AACC Press, Washington, DC. Chapter 23 Laboratory Diagnosis of Liver Disease, Pp 269 - 279.

Wu, A. (2006). Tietz Clinical Guide to Laboratory Tests, Fourth Edition. Saunders Elsevier, St. Louis, Missouri. Pg 652.

(2007 March 13, Updated). LDH. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003471.htm. Accessed on 7/9/07.

Vorvick, L. and Zieve, D. (Updated 2009 March 14). LDH isoenzymes. MedlinePlus Medical Encyclopedia [On-line information] Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003499.htm. Accessed October 2010.

Vorvick, L. and Zieve, D. (Updated 2010 March 21). Lactate Dehydrogenase Test. MedlinePlus Medical Encyclopedia [On-line information] Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003471.htm. Accessed October 2010.

Shaffer, E. (Revised 2009 June). Testing for Hepatic and Biliary Disorders, Laboratory Tests. Merck Manual for Healthcare Professionals [On-line information] Available online at http://www.merck.com/mmpe/sec03/ch023/ch023b.html through http://www.merck.com. Accessed October 2010.

(© 1995-2010). Unit Code 8344: Lactate Dehydrogenase (LD), Serum. Mayo Clinic, Mayo Medical Laboratories [On-line information] Available online at http://www.mayomedicallaboratories.com/test-catalog/Overview/8344 through http://www.mayomedicallaboratories.com. Accessed October 2010.

Blood Test: Lactate Dehydrogenase (LDH). KidsHealth from Nemours Foundation [On-line information] Available online at http://kidshealth.org/parent/system/medical/test_ldh.html through http://kidshealth.org. Accessed October 2010.

Pagana, K. D. & Pagana, T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 581-583.

Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 648-651.

Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Burtis CA, Ashwood ER, Bruns DE, eds. St. Louis: Elsevier Saunders; 2006, Pp 601-602.

National Cancer Institute. Tumor Markers. Avaialble online at http://www.cancer.gov/cancertopics/factsheet/Detection/tumor-markers through http://www.cancer.gov. Accessed October 2013.

American Cancer Society. Specific tumor markers. Available online at http://www.cancer.org/treatment/understandingyourdiagnosis/examsandtestdescriptions/tumormarkers/tumor-markers-specific-markers through http://www.cancer.org. Accessed October 2013.

KidsHealth. Blood Test: Lactate Dehydrogenase (LDH). Available online at http://kidshealth.org/parent/system/medical/test_ldh.html through http://kidshealth.org. Accessed October 2013.

National Cancer Institute. Testicular Cancer Treatment (PDQ®). Available online at http://www.cancer.gov/cancertopics/pdq/treatment/testicular/HealthProfessional/page1#Section_562 through http://www.cancer.gov. Accessed October 2013.

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