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Myoglobin - serum
Definition
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
Alternative Names
Serum 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 Results
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
Risks
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)
References
Amato AA, Brooke MH. Disorders of skeletal muscle. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier;2008:chap 83.
Barohn RJ. Muscle diseases. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 447.
O'Connor FG, Deuster PA. Rhabdomyolysis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 114.
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
