LDH isoenzyme blood test
The lactate dehydrogenase (LDH) isoenzyme test checks how much of the different types of LDH, called isoenzymes, are present in the blood.
Lactate dehydrogenase
Lactate dehydrogenase (LDH) is a protein that helps produce energy in the body. An LDH test measures the amount of LDH in the blood.
Read Article Now Book Mark ArticleHow the Test is Performed
A blood sample is needed.
Blood sample
Venipuncture is the collection of blood from a vein. It is most often done for laboratory testing.
How to Prepare for the Test
The health care provider may tell you to temporarily stop taking certain medicines before the test.
Drugs that can increase LDH measurements include:
- Anesthetics
- Aspirin
- Colchicine
- Clofibrate
- Cocaine
- Fluorides
- Mithramycin
- Narcotics
- Procainamide
- Statins
- Steroids (glucocorticoids such as hydrocortisone or prednisone)
Do not stop taking any medicine before talking to your provider.
How the Test will Feel
When the needle is inserted to draw blood, some people feel slight pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.
Why the Test is Performed
LDH is an enzyme found in many body tissues such as the heart, liver, kidney, skeletal muscle, brain, blood cells, and lungs. When body tissue is damaged, LDH is released into the blood.
Enzyme
Enzymes are complex proteins that cause a specific chemical change. For example, they can help break down the foods we eat so the body can use them....
Read Article Now Book Mark ArticleThe LDH test helps determine the location of tissue damage.
LDH exists in five forms, which differ slightly in structure.
- LDH-1 is found primarily in heart muscle and red blood cells.
- LDH-2 is concentrated in white blood cells.
- LDH-3 is highest in the lung.
- LDH-4 is highest in the kidney, placenta, and pancreas.
- LDH-5 is highest in the liver and skeletal muscle.
All of these can be measured in the blood.
What Abnormal Results Mean
LDH levels that are higher than normal may suggest:
- Hemolytic anemia
Hemolytic anemia
Anemia is a condition in which the body does not have enough healthy red blood cells. Red blood cells provide oxygen to body tissues. Normally, red ...
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- Infectious mononucleosis
Infectious mononucleosis
Mononucleosis, or mono, is a viral infection that causes fever, sore throat, and swollen lymph glands, most often in the neck.
ImageRead Article Now Book Mark Article - Intestinal ischemia (blood deficiency) or infarction (tissue death)
- Ischemic cardiomyopathy
Ischemic cardiomyopathy
Cardiomyopathy is disease in which the heart muscle becomes weakened, stretched, or has another structural problem. It often contributes to the hear...
ImageRead Article Now Book Mark Article - Liver disease such as hepatitis
Hepatitis
Hepatitis is swelling and inflammation of the liver.
ImageRead Article Now Book Mark Article - Lung tissue death
- Muscle injury
- Muscular dystrophy
Muscular dystrophy
Muscular dystrophy (MD) is a group of inherited disorders that cause muscle weakness and loss of muscle tissue, which get worse over time.
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- Stroke
Stroke
A stroke occurs when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack. " If blood flow is cut off for longer th...
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Risks
There is little risk in having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
- Multiple punctures to locate veins
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Reviewed By
Jacob Berman, MD, MPH, Clinical Assistant Professor of Medicine, Division of General Internal Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Pincus MR, Carty RP. Clinical enzymology. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 21.
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