LDH isoenzymes
Key points
- This is a test that measures the amount of the isoenzymes (different forms) of lactate dehydrogenase (LDH) in blood serum.
- Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand.
- The area is cleansed with antiseptic and punctured with a sharp needle or a lancet.
- The health care provider may advise you to withhold drugs that may affect the test.
Alternative names
LD; Lactic (lactate) dehydrogenase isoenzymes
Definition
This is a test that measures the amount of the isoenzymes (different forms) of lactate dehydrogenase (LDH) in blood serum.
How the test is performed
Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic. An elastic band or blood pressure cuff is placed around the upper arm to cause veins to swell with blood.
A needle is inserted into a vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore circulation. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
For infants or young children:
The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.
How to prepare for the test
The health care provider may advise you to withhold drugs that may affect the test. (See special considerations.)
For infants and children:
The preparation involved in readying a child for any test or procedure depends on the child's age, interests, previous experiences, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:
- Infant test or procedure preparation (birth to 1 year)
- Toddler test or procedure preparation (1 to 3 years)
- Preschooler test or procedure preparation (3 to 6 years)
- Schoolage test or procedure preparation (6 to 12 years)
- Adolescent test or procedure preparation (12 to 18 years)
How the test will feel
When the needle is inserted to draw blood, some people may feel moderate pain, while others may feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
This test is usually performed when elevated LDH levels are suspected. Measurement of LDH isoenzymes helps determine the location of tissue damage.
Written and revised by
Gerald Hurowitz, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
health.am provides general information, not medical advice. Always consult a qualified health professional about your own health.