Definition of Myoglobin - serum:

Serum myoglobin is a test that measures the amount of myoglobin in the blood.

Myoglobin is a protein in heart and skeletal muscles. When you exercise, your muscles use up any available oxygen. Myoglobin has oxygen attached to it, which provides extra oxygen for the muscles to keep at a high level of activity for a longer period of time.

When muscle is damaged, myoglobin is released into the bloodstream. The kidneys help remove myoglobin from the body into the urine. In large amounts, myoglobin can damage the kidneys.

See also: Urine myoglobin

How the test is performed:

A blood sample is needed. For information on how this is done, see: Venipuncture

How to prepare for the test:

There is no special preparation.

How the test will feel:

When the needle is inserted to draw blood, you may feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the test is performed:

Myoglobin levels may be obtained to confirm suspected muscle damage, including heart and skeletal muscle damage.

Normal Values:

The normal ("negative") range is 0 - 85 nanograms per milliliter (ng/mL).

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

What abnormal results mean:

Greater-than-normal levels (a "positive" result) may indicate:

• Heart attack
• Malignant hyperthermia (very rare)
• Muscular dystrophy
• Rhabdomyolysis
• Skeletal muscle inflammation (myositis)
• Skeletal muscle ischemia (blood deficiency)
• Skeletal muscle trauma

What the risks are:

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient 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 light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)